2006 Acura MDX Press Kit

2006 Acura MDX - Overview

Overview

The 2001 Acura MDX™ was launched in 2000 to define a new era in the evolution of luxury sport utility vehicles, treading beyond the limits of existing SUVs in terms of handling, packaging efficiency and environmental impact. It was developed with the overriding goal of setting new benchmarks for luxury SUV performance. That performance goal applies to the three main themes of the development concept; to establish new performance benchmarks in the SUV category for versatility, responsibility and dynamic performance. As the development process progressed, an additional development goal was added - furnishing the vehicle with an array of cutting edge features that effectively "defeat winter" for its driver and passengers - limiting the harsh effects of the cold winter months on MDX occupants.

The MDX had a stellar first year, establishing itself as the #1 SUV by capturing both the Motor Trend Sport Utility of the Year and the North American Truck of the Year awards. In the following years, Acura proceeded to make it even better, increasing its already formidable performance and further refining the MDX inside and out. For 2003, a new engine boosted horsepower from 240 to 260, a new 5-speed automatic transmission was added and the chassis and suspension were enhanced to take advantage of the additional power. A new drive-by-wire throttle system was included and the state-of-the art VTM-4® four-wheel drive system was revised to provide enhanced vehicle control during acceleration, cornering and braking.

The 2004 model year MDX received exterior styling enhancements that gave it a muscular, performance-oriented look representative of its impressive powertrain. Last year, the MDX received a host of technological and safety upgrades, including standard XM® Satellite Radio, an enhanced optional Acura Navigation System with Voice Recognition™ and the addition of the OnStar system and HandsFreeLink™ wireless phone interface on the Touring Package. Standard safety features such as an improved Vehicle Stability Assist (VSA®) system and Brake Assist, which helps drivers apply full braking pressure in an accident avoidance situation were added to the 2005 MDX.

For the 2006 model year, the MDX receives an assortment of stylish and sporty additions to the interior. High quality ebony-colored Zebra wood garnishes the center console and door switches and refined Satin Chrome accents are added to models equipped with the Touring Package. The MDX also adds a new exterior color, Amazon Green Metallic.

Performance Attributes Overview

Outstanding performance has always been a fundamental Acura character trait. The development of Acura's first in-house designed and engineered SUV presented the opportunity for the engineers to sidestep the shortcomings of products already on the market and begin with a fresh approach to the SUV equation. That approach was to create the first no-compromise SUV - melding attractive design, unmatched versatility, driving exhilaration, social responsibility, and value in one neatly wrapped package.

The MDX is powered by a 3.5-liter, V-6 engine, tuned to deliver an outstanding 253 peak horsepower SAE net (8/04)* at 5800 rpm and 250 lbs-ft of torque SAE net (rev 8/04) at 3500 rpm. Providing V-8-like power, this engine is coupled to a compact 5-speed automatic transmission and a drive-by-wire throttle system (DBW) that deliver precise shifts and reduced shift shock. The MDX's standard VTM-4 four-wheel drive system works seamlessly with the DBW and the standard Vehicle Stability Assist (VSA) system to enhance performance on low traction surfaces, and enhance stability in all conditions.

The MDX's 4500-pound boat towing package (3500-pound for trailers) was achieved by tuning the powertrain and chassis systems to manage heavy loads with confidence. This vehicle's wider-than-normal stance, high-torque engine, wide-ratio 5-speed automatic transmission, and powerful brakes yield a highly competent tow vehicle.

*For the 2006 model year, horsepower and torque specifications for all Acura models have been updated in press materials to reflect the revised Society of Automotive Engineers (SAE) J1349 (Rev 8/04) net calculations. These new specifications reflect a number of significant differences from the old test procedures and may cause horsepower and torque totals published in 2006 media materials to differ from the figures published in previous years. To avoid confusion, all 2006 Acura press materials will specify SAE net (Rev 8/04) after all horsepower and torque figures to denote adherence to the new standards.

Acceleration, Braking, Cornering Performance

A pillar of the Acura development approach is that the driver's seat should be the most rewarding seat in the vehicle. With this in mind, the development team groomed the MDX to behave like a sports sedan when driven in an assertive manner. The starting point is a 3.5-liter SOHC V-6 engine that combines a remarkably broad range of torque - 253 lbs-ft between 3500 and 5000 rpm - with a potent 253 horsepower SAE net (8/04)at 5800 rpm. Factor in a wide-ratio, 5-speed automatic transmission and a sensible curb weight achieved by the shrewd use of high-strength materials, and MDX posts outstanding acceleration performance.

Acknowledging that ordinary SUVs feel clumsy and cumbersome, extra effort was invested in making sure that the MDX provides driving exhilaration consistent with Acura standards. Chassis systems and the power-to-weight ratio are optimized for all-around performance.

The MDX features 4-channel Vehicle Stability Assist (VSA) with active yaw control for increased driver control during accident avoidance maneuvers, aggressive cornering and inclement weather. The VSA system monitors lateral (cornering) stability and seamlessly integrates traction control, 4-wheel drive, Anti-lock braking, throttle control and stability control functions.

Demanding drivers expect a vehicle's braking system to match its acceleration - and MDX measures up to that task as well. To provide short stopping distances, high fade resistance, and a reassuring pedal feel, the MDX's four-wheel disc braking system uses large-diameter rotors, extra-rigid calipers and dual-piston front calipers. The 4-channel Anti-lock Braking System (ABS) features electronic distribution of brake forces for optimum use of the traction available at each corner of the vehicle and Brake Assist. The result is responsive braking performance for short stopping distances with a confident pedal feel.

Excellent handling begins with getting the fundamentals of vehicle dynamics right from the start. A wide track maximizes stability and cornering grip, so MDX has the widest track in its class. The MDX design was tuned to achieve the best possible maneuverability and helps to minimize the cumbersome feeling that plagues most truck-based SUVs.

To overcome the usual ride-versus-handling compromises, engineers incorporated front and rear subframes to isolate road noise and driveline vibration from the passenger compartment, along with independent front and rear suspension systems with extra wheel travel and fine-tuned suspension geometry. Low roll centers combined with large stabilizer bars provide progressive, predictable cornering response and excellent stability at the limit of adhesion. Lightweight materials - such as aluminum castings for all major driveline components and extensive use of high strength steel unit body components - give MDX an overall agile feeling.

The Versatile SUV

The theme of versatility was applied to each area of development, from exterior and interior styling to powertrain to chassis design and the many performance targets. From the inside out, MDX offers many options to the driver and passengers including the potential for six seating configurations from the split and folding second and third-row seats.

The options don't end there however, as the powertrain is tuned for optimum performance in virtually any condition the driver is likely to encounter. Key to this is an engine that is powerful, fuel efficient and low in emissions - with a broad range of torque and horsepower. Likewise, the 5-speed transmission offers one of the widest overall gear ratio ranges in the segment, ensuring that engine speeds are matched as closely as possible to the demands of the driving conditions at any time.

MDX's unit body construction provides the optimum balance of strength and rigidity while still being the most space and weight efficient construction for an SUV of this size. All suspension, steering and braking components are designed to minimize unsprung weight to improve handling precision, but are still rugged enough for medium-duty, off-road driving. Structural enhancements allow all MDX models to further enhance safety.

The Responsible SUV

MDX demonstrates a high degree of environmental responsibility by providing excellent fuel economy with very low exhaust emissions. Thanks in part to a high output exhaust system, and innovative fuel injectors, the MDX meets stringent LEV-2 ULEV emissions levels. The shape of the gas tank increases capacity and reduce sloshing noise while also helping the MDX meet LEV-2 Evaporative standards. The MDX's combination of 17 mpg city and 23 mpg highway places it ahead of many competitive luxury SUVs in fuel economy and proves that powerful SUVs can be environmentally responsible and fuel efficient.

Safety has been an integral part of the MDX design from its inception, and an important aspect of the responsible SUV concept. To help avoid situations that could lead to a collision, MDX is engineered with the agility and maneuverability necessary to help maintain control in emergency maneuvers.

When a collision is unavoidable, MDX helps protect its occupants with a reinforced body structure and state-of-the-art occupant protection features. The MDX features front dual-stage, dual-threshold airbags, driver and front passenger side airbags and a Side Curtain Airbag system to help protect vehicle occupants from head and neck injuries in the event of a sufficient side impact. A Tire Pressure Monitoring System uses sensors in the wheels to alert the driver when tire pressure drops below 25 percent of the recommended level.

Medium Duty Off-Road Capability

The engineers who designed the MDX tested a range of competitive SUVs to help quantify off-pavement use patterns, customer needs, and engineering targets for the MDX. Accommodating extreme off-road use can impose compromises elsewhere in the vehicle, such as added weight, awkward entry and egress, poor fuel economy, and reduced on-road performance. With this in mind, the MDX team visited nine off-road parks in California, Nevada, Kentucky, North Carolina, and Michigan to study SUVs in their natural, off-road habitat. While a few competitors offer the extra ground clearance, driveline equipment, and chassis hardware necessary to support ambitious off road excursions, the engineers learned that few customers use these extreme capabilities regularly.

After observing casual off-roaders, MDX engineers concluded that surpassing the class's most capable off-road machine was not in MDX's best interests and that a medium-duty off-road capability was most consistent with the philosophy embraced by the MDX. Medium-duty capability would readily support trips into the wilderness for camping or to launch a boat without providing the rigorous equipment needed to conquer the extremes of the Rubicon Trail.

To define exactly what constitutes medium-duty off-road capability, the MDX engineering team selected 14 key performance criteria based on observations of casual off-road adventurers. They then constructed special test courses at their R&D facilities in North America to assure that MDX delivers all the intended capabilities with impeccable reliability and durability.

The list of test courses includes:

• 30-degree dirt hill
• Sand hill
• Water pit
• Rock roads
• Embedded log course
• Step-up, step-down
• Sand drag strip
• Gully course
• Ground contact course
• Washboard road
• Frame twister
• Power hop hill (23-degree slope with rippled surface)
• Gravel road
• Startable grade

Numerous engineering changes were based on experiences gained in testing. These included:

• A deeper oil pan was included to meet the hill climbing criteria.
• A more effective air filter was specified to remove dust from the engine's air supply.
• The tow hooks were upgraded to handle loads imposed during extraction from "stuck vehicle situations.
• Waterproofing was added to support MDX's ability to traverse up to18-inch-deep bodies of water.
• Throttle actuation was calibrated to provide more sensitive control over engine output at low speeds.

For an acid test, engineers took prototype vehicles for a 200-mile off-road test on the Mojave Trail located in Southern California. This gauntlet of loose rocks, sandy washes, twisting grades, and narrow escarpments helped ensure that MDX has what it takes to venture off road and home again with confidence.

The results speak for themselves - MDX will climb a 31-degree (60-percent) paved slope with a two-passenger load. It has eight inches of ground clearance, a 28-degree approach angle, a 21-degree departure angle, and a 21-degree breakover angle for negotiating rough terrain. It can claw up a 28-degree (53-percent) dirt slope from a dead stop.

Towing

One of the reasons people buy SUVs is to be able to haul pop-up campers, medium-sized boats, and recreational vehicle trailers. To understand this facet of the MDX's makeup, MDX engineers polled focus groups and studied survey results that tapped 200,000 households. Their findings offered the insights needed to properly outfit the MDX to surpass the towing expectations of most customers.

Ultimately, the engineers concluded that a casual or weekend towing capability was most appropriate for MDX. Customer feedback helped set the towing limit at 4500 pounds for boats and 3500 pounds for other types of trailers. A heavier load is acceptable with boats because their pointed bow shapes impose less aerodynamic drag on the towing vehicle than a slab-faced, square-cornered trailer. The 3500/4500-pound rating is calculated to include up to four passengers and their cargo.

Variable Torque Management ® 4-Wheel Drive System (VTM-4®)

The MDX is equipped with an advanced 4-wheel drive system - VTM-4. The VTM-4 system consists of a pair of computer controlled wet clutches in the rear axle that work to maintain traction in all types of conditions.

Unlike other on-demand 4-wheel drive systems, MDX doesn't wait for slippage to occur before going to work. Instead, torque is proactively delivered to the rear wheels in proportion to forward acceleration to supplement front-wheel drive. This innovative, proactive approach pays two dividends: on dry pavement, there's less likelihood of torque steer (a tendency for propulsion forces to tug at the steering and nudge the vehicle off line) and there is more front tire adhesion available for cornering. In snow or wet conditions, automatic and proactive all-wheel drive gets the vehicle moving from a standstill with less chance of wheelspin.

If conditions are really slippery and wheel spin is unavoidable, VTM-4 instantly reacts by adding rear-wheel torque in proportion to both the slippage and the rate of increase of slippage. This enhances performance on low traction surfaces and also improves steering trace and feel during acceleration. In addition, the VSA system further increases traction in different conditions by providing a limited-slip differential effect for the front wheels.

A special lock mode is also provided to help extract the vehicle from a stuck condition. To use this get-out-of-a-snowbank capability, the driver moves the shift lever to first, second or reverse and presses the VTM-4 lock button on the dash. With the lock mode engaged, VTM-4 "locks" the rear axle to provide maximum power transfer to each rear wheel. As speed increases above six mph, the system automatically reduces the lock effect to the rear axle. By 18 mph, the system reverts to normal mode.

Defeat Winter Objective

While studying competitive vehicles and the SUV marketplace, the MDX development team discovered that a well-designed product could be an effective defense against some of the frustrating rituals of the coldest months of the year. Based on that insight, members of the MDX development team that had grown up in northern parts of the U.S. drew on their personal backgrounds to formulate a clever "defeat winter" objective for MDX - consisting of a long list of designed-in features and systems designed to provide superior cold-weather performance. The result is that MDX can be a major confidence builder for those faced with driving through severe winter road conditions.

The MDX's winter-beating tactics begin with a chassis engineered for excellent dynamics on wet, icy, or snowy pavement, the VTM-4 all-wheel-drive system and Vehicle Stability Assist (VSA). Various other chassis details are also engineered with a priority on winter driving. MDX's Goodyear and Michelin tires are compounded with silica to enhance ice and snow traction at cold temperatures. Testing has demonstrated that the grip of these tires is superior to many of the snow tires currently on the market. MDX's front suspension has a very low scrub radius so that braking on split-friction surfaces (such as when one side of the vehicle is on ice and the other side is on dry pavement) does not tend to pull the vehicle in one direction or the other.

Total roll stiffness is equitably distributed so that cornering response is linear and predictable even at low lateral Gs experienced during slippery conditions. The driveline is designed to provide natural and neutral handling response on snow and ice. With a static ground clearance of 8 inches, MDX is unlikely to get mired in snow drifts. The Anti-lock Braking System (ABS) is equipped with electronic brake-force distribution and four channels to provide maximum steering control even when traction varies dramatically from wheel to wheel. To preserve lateral stability, the rear brakes are programmed with a select-low strategy to modulate line pressure at both rear wheels as soon as either one approaches lock-up.

Features and amenities included as MDX standard equipment further enhance its winter-driving prowess. The rear heater is electronically linked to the operation of the front heater to speed warm up after a cold start and heat is ducted to all seating positions.

Electrically heated front seats and window defoggers are standard. Rear splash guards are provided to deflect slush and stones away from the side of the vehicle. Extra seals positioned at the bottom of the doors keep mud and slush from building up on lower surfaces that are likely to contact long coats, pant legs or dresses. Likewise, the windshield molding and the outside rearview mirror mounting trim are shaped to guide moisture flow away from the side windows for optimum foul-weather visibility. Door-mounted rearview mirrors are electrically heated to clear frost and fog.

MDX models equipped with the Touring Package are equipped with rain-sensing windshield wipers that, when in automatic mode, adjust wiper speed to correspond to the amount of rain that is contacting the windshield. The windshield washer reservoir is a large 1.2 gallons for a generous supply of washer fluid, and an indicator light advises the driver when it's time to replenish that fluid. Washer nozzles are engineered for optimum performance with a fluidic design in front and a jet-type sprayer in back. Since remote keyless entry is standard equipment on MDX, owners will not be kept from entering their vehicle by a frozen lock cylinder.

2006 Acura MDX - Powertrain

Introduction

An advanced powertrain is essential to meet the MDX's goals of providing V-8-like performance, class-leading low emissions, and excellent fuel economy. To that end, the MDX is powered by an advanced 3.5-liter, VTEC V-6 engine. The MDX powerplant produces 253 horsepower SAE net (8/04)at 5800 rpm, and 250 lb-ft SAE net (8/04) of torque at 3500 rpm. Acura's Variable Valve Timing and Lift Electronic Control (VTEC™) valvetrain, first used in the NSX supercar, adjusts the timing, duration, and lift of the intake valves according to engine speed. In conjunction with a two-stage intake manifold, VTEC yields muscular response at low- and medium-rpm, high peak-rpm performance, very low emissions, and superior fuel efficiency. A dual exhaust system increases horsepower and torque while helping to minimize emissions.

The powerful engine is coupled to an innovative drive-by-wire throttle system, which eliminates the need for a mechanical connection between the cockpit and engine, reduces overall weight by incorporating the cruise control function and helps to reduce shift shock by communicating with the transmission during up and down shifts.

The MDX's compact 5-speed, automatic transmission utilizes a super-flat torque converter and a 4-shaft layout that relocates the third gear clutch to reduce overall length while increasing torque capacity. Furthermore, an innovative shaft center layout of the idle row gear reduces the amount of gear inclination during driving, thereby reducing gear noise. This transmission boasts several features engineered specifically for use in a mid-sized luxury SUV, including: wide gear ratios to optimize both start-up acceleration and highway cruising comfort, a lock-up torque converter for maximum efficiency and a rigid alloy case design for light weight.

The MDX's innovative VTM-4 (Variable Torque Management® 4-Wheel Drive) all-wheel drive system works with the Vehicle Stability Assist (VSA) to provide extra traction during acceleration and when encountering slippery road conditions. Additional VTM-4 benefits are improved dry-road vehicle dynamics, medium-duty off-road capability, and a lock feature to aid extraction from severe "stuck" conditions. A compact transfer case is bolted directly to MDX's front-mounted transaxle. A two-piece propeller shaft delivers torque from the transfer case to a rear axle drive unit and two computer-controlled, electromagnetically-powered clutches engage as needed to provide torque to the rear wheels. The VTM-4 system provides up to a 30 percent increase in rear torque for enhanced handling and increased steering feel, especially in slippery situations.

Powertrain Summary

Engine

• 3.5-liter 60-degree V-6 with belt-driven single-overhead camshafts and four valves per cylinder
• 253 horsepower SAE net (rev 8/04) at 5800 rpm; 250 lb-ft of torque SAE net (rev 8/04)at 3500 rpm
• Broad and flat torque curve with 95-percent of peak output available from 2500 to 5500 rpm
• High-flow dual-exhaust system
• Variable Valve Timing and Lift Electronic Control (VTEC)
• Drive-by-wire throttle system
• Computer-controlled Programmed Fuel Injection (PGM-FI)
• Dual-stage induction system
• Direct Ignition system
• 105,000-mile tune-up intervals

5-speed Automatic Transmission

• Wide-ratio design provides a first gear with extra pulling power to start heavy loads in combination with a high top gear for quiet highway cruising
• Components are engineered to provide the durability needed for on-road, off-road and towing use

Variable Torque Management 4-Wheel Drive (VTM-4)

• Uses integral, single-speed transfer case, two-piece propeller shaft, and electromagnetically-actuated clutches in a rear axle drive unit to provide the best of all-wheel drive and part time 4-wheel drive
• Optimum vehicle dynamics during both dry and slippery conditions
• Extra traction and stability on snow and wet roads
• Rear-driving traction for off-road use
• Lock feature for getting unstuck in slippery conditions

Fuel Economy and Exhaust Emissions

• Fuel economy ratings of 17 mpg in city driving and 23 mpg on the highway*
• Exhaust system uses two close-coupled primary catalyzers, and an underfloor secondary catalyzer
• All MDX models are designed to meet LEV-2 ULEV emissions standards

*Based on 2006 EPA mileage estimates

Engine Architecture

The Acura MDX's engine is an advanced 3.5-liter, SOHC, 24-valve, 60-degree, V-6, aluminum-block-and-head design that is compact, light and powerful. A long list of technologies has been engineered to provide 253 horsepower SAE net (rev 8/04), a broad and flat torque curve, very low emissions, high fuel efficiency, and instantaneous throttle response. The VTEC valvetrain and dual-stage intake manifold optimize cylinder filling efficiency across the engine's entire operating range. Low-restriction intake and exhaust systems, a 10.0:1 compression ratio, and roller-type rocker arms also aid efficiency.

Engine Block

The MDX's 3.5-liter die-cast engine block is made from heat-treated aluminum to minimize weight. A deep-skirt configuration rigidly supports the crankshaft, minimizing noise and vibration. Thin-wall, centrifugally-cast iron liners help reduce overall length and weight. Each liner's rough as-cast exterior surface bonds securely to surrounding aluminum during the manufacturing process to increase strength and enhance heat transfer.

Crankshaft/Connecting Rods/Pistons

A forged-steel crankshaft is used for maximum strength, rigidity, and durability with minimum weight. Instead of bulkier, heavier nuts and bolts, connecting rod caps are secured in place with smaller, high-tensile-strength fasteners that screw directly into the connecting rod. Short-skirt, cast-aluminum, flat-top pistons are notched for valve clearance and fitted with full-floating piston pins.

Cylinder Head

The MDX utilizes innovative cylinder heads that include tuned exhaust manifolds as an integral part of the casting. Made of pressure-cast, low-porosity aluminum, these lightweight components improve overall packaging, enhance exhaust flow and permit optimal positioning of the primary close coupled catalytic converters.

Unlike many SUVs, the Acura MDX has four-valve combustion chambers, the best approach to optimum performance with excellent fuel efficiency and very low emissions.

Valves are clustered near the center of the bore to minimize combustion chamber volume and to provide ample squish area. A 10.0:1 compression ratio helps maximize thermal efficiency, power output, and fuel mileage. One centrally located camshaft per bank is driven by a fiberglass-reinforced toothed belt. Head gaskets are made of high-strength materials to contain combustion pressures.

Variable Valve Timing and Lift Electronic Control (VTEC™)

The MDX's innovative Variable Valve Timing and Lift Electronic Control (VTEC) is one key to maximizing engine output across the full operating range. The high-rpm induction lobes of the camshaft provide additional valve lift to help increase peak horsepower. Ordinary engines have fixed valvetrain parameters - the same timing of valve lift and overlap whether the tachometer needle is struggling to climb out of the low-rpm range or screaming at the redline. The VTEC approach, however, has two distinct modes so that operation of the intake valves changes to optimize both volumetric efficiency (breathing) and combustion of the fuel-air mixture. In order to achieve the optimum valmetric efficiency in the lower portion of the engine's operating range, rocker arms are programmed to follow cam lobes that provide low lift and reduced duration (shorter time open with less valve lift).

At 4400 rpm, the MDX's powertrain control module commands the VTEC system to switch intake valve operation to the high-rpm mode. In response, an electric spool valve opens to route pressurized oil to small pistons within the intake-valve rocker arms. These pistons then slide to lock the three rocker arms provided for each cylinder together. As a result, both intake valves follow a central high-lift, longer-duration cam lobe. The switching process takes just 0.1 second and is undetectable by the driver.

The extra lift and longer duration provide the added air and fuel the engine needs to produce high peak horsepower and a broader torque band. Instead of a peaky engine, the MDX has a powerplant that provides excellent performance at any engine speed.

Dual-Stage Induction System

The induction system atop the MDX's V-6 engine works in concert with the VTEC valvetrain to significantly boost torque across the engine's full operating range. Internal passages and two butterfly valves commanded by the powertrain control module are configured to provide two distinct modes of operation. The valves are closed at lower rpms. In this mode, the three cylinders on each bank draw air from only the nearer half of the manifold's internal chamber, or plenum. The volume of the plenum and the length of inlet passages are both tuned to maximize the resonance effect, wherein pressure waves are amplified within each half of the intake manifold at certain rpm ranges. The amplified pressure waves significantly increase cylinder filling and the torque produced by the engine throughout the lower part of its rpm band. Funnel-shaped intake ports - similar to those used on racing engines - are built in at the uppermost end of each intake runner to improve air flow.

As the benefits of the resonance effect dwindle with rising rpm, the butterfly valves open at 3700 rpm to interconnect the two halves of the plenum, doubling its volume. An electric motor commanded by the powertrain control module opens directly and closes the connecting butterfly valves. Now each cylinder draws intake air from the full plenum chamber. The inertia of the mass of air rushing down each intake passage helps draw in more charge than each cylinder would normally ingest. This phenomenon is the same effect produced by a low-pressure supercharger. The inertia effect greatly enhances cylinder filling efficiency and the torque produced by the engine at higher rpm. Concurrently, the VTEC system has switched from low-speed to high-speed valve timing to further enhance air flow through the intake valves and into each cylinder.

The net effect of the MDX's dual-stage intake manifold and VTEC valve train is that MDX delivers more torque and power than many of the large V-6s and small V-8s used by the competition, while also providing superior fuel efficiency and very low emissions. More than 95-percent of peak torque is available from 2500 to 5500 rpm.

Programmed Fuel Injection (PGM-FI)

Fuel is delivered in sequence and timed to each cylinder's induction stroke by six injectors mounted on the lower portion of the intake manifold. The MDX was the first Acura vehicle to feature innovative orifice-type injectors instead of pintle-type injectors. These injectors, first implemented in the 2003 model, optimize the fuel spray pattern, and improve fuel atomization for increased fuel mileage and reduced emissions. A 32-bit, 40MHz central processor unit (CPU) within the MDX's powertrain control module calculates injection timing and duration after assessing an array of sensor signals: crankshaft and camshaft position, throttle position, coolant temperature, intake manifold pressure and temperature, atmospheric pressure, and exhaust-gas oxygen content. The CPU controlling the MDX's Programmed Fuel Injection (PFM-FI), VTEC valve train, dual-stage intake manifold and the transmission also communicates with CPUs that regulate the drive-by-wire throttle, the Variable Torque Management 4-wheel-drive system and the Vehicle Stability Assist (VSA).

Drive-by-Wire Throttle

The MDX features an innovative drive-by-wire throttle system with technology gleaned from the NSX sports car. This second generation drive-by-wire system replaces a conventional throttle cable arrangement with an all-electronic system that senses the throttle pedal position and relays that information to a computer. The computer then performs the actual throttle activation instantaneously. Unlike the NSX system, this system utilizes a DC motor instead of a Step Motor within the throttle body.

The MDX drive-by-wire system works by means of a throttle pedal sensor, a throttle angle sensor, an electronic control unit and a DC motor to control throttle opening and provide fail-safe throttle operation. This system allows for throttle control to be integrated into the VSA and VTM-4 systems and also incorporates the cruise control function. To improve shifting smoothness, the drive-by-wire system controls the throttle during transmission shifts. To maximize driving feel, throttle pedal characteristics are calibrated to be smooth and linear during start up, when driving on ice or other low traction surfaces, and more responsive during acceleration.

Serpentine Drive Belt

The MDX uses a single, serpentine belt to operate all of the engine's accessory drives. In addition to saving space compared to the dual-belt system used on the previous generation engine, this maintenance-free component features an integral auto tensioner.

Direct Ignition System and Knock Control

Maintaining the correct ignition timing throughout all operating conditions is essential to producing maximum power, using fuel efficiently and minimizing emissions. A powertrain control module (PCM) examines various engine functions as well as a block-mounted acoustic knock sensor to determine optimum ignition timing. In the event the engine is supplied with fuel lower in octane than the specified unleaded premium, the PCM retards ignition timing as needed to forestall detonation. As a result, the engine constantly operates at the point of peak efficiency. Spark is supplied to iridium-tipped, long-life spark plugs by six coil units positioned directly over the plugs in the cylinder-head access bores.

105,000 mile Tune-Up Intervals

Before 105,000 miles of driving, the only maintenance necessary is routine inspections and fluid and filter changes. At 105,000 miles, the valves should be adjusted, the timing belt should be replaced, the water pump should be inspected and the iridium-tipped spark plugs should be replaced.

Exhaust System

The MDX employs a high-flow dual exhaust system that helps to generate additional horsepower while still maintaining strict emissions standards. A low-restriction, high-flow exhaust system is crucial to efficient power and torque production. The MDX features a high efficiency system that incorporates several key elements that work in concert with the engine's uniquely designed cylinder heads to help boost performance, reduce tailpipe emissions and trim weight. Major system components include two close-coupled catalytic converters, a secondary underfloor catalytic converter, a centrally positioned, high-flow resonator and a silencer. The close coupled catalytic converters provide almost double the surface opening of the single underfloor unit they replace and mount directly to the cylinder head to reduce light off time, thereby allowing the catalyst to begin cleansing the exhaust as soon possible.

The catalysts, muffling element, and piping are all sized for high flow and low restriction. High-chromium stainless steel is used throughout the exhaust system for excellent durability. The twin exhaust outlets are polished for an attractive appearance.

5-speed Automatic Transaxle

The MDX features a compact 5-speed automatic transmission that utilizes a 4-shaft design layout. This configuration, together with a super flat torque converter allows for a more compact transmission while that produces higher torque capacity to match the powerful engine. The shape of the differential gear and the shape of the oil sump help to reduce the collection of oil in the pan and separate the oil from the gears. This reduction in friction improves efficiency, thereby boosting performance.

A lock-up torque converter is provided to maximize fuel efficiency. Torque-converter lock-up and shift timing are both managed by a 32-bit, PGM-FI CPU that maintains a communications link with the engine's CPU. Gear and clutch materials and the transaxle case itself are all engineered to support towing, off-road driving, and 4-wheel-drive use.

This unit's design utilizes extra-wide gear ratios, which enhance low-speed pulling capability, fuel economy and the ability to cruise quietly on the highway.

Creative use of clutched idler gears permits the transaxle to provide five forward speeds with little more weight or bulk than a typical four-speed automatic. A one-way clutch is provided for first gear to smooth upshift quality. An extra-capacity transmission fluid cooler is offered with the MDX's optional tow package to maintain acceptable lubricant temperatures during heavy-load conditions.

A direct-control strategy provides real-time pressure management of the transmission's clutches. Various safety and control strategies coordinate engine and transmission operation. For example, driveline shocks during up- or downshifts are minimized by momentarily reducing engine torque during the shift. In neutral and park, engine rpm is automatically limited to 5000 rpm.

For driving through hilly terrain, a Grade Logic Control system monitors throttle position, vehicle speed, acceleration and deceleration to avoid hunting and excessive shifting. A lower gear is held for a longer-than-normal period to provide better climbing ability on hills and more engine braking on downhill grades.

Variable Torque Management 4-Wheel-Drive (VTM-4®) System

After studying various all-wheel- and four-wheel-drive systems offered by the wide variety of SUVs on the market today, MDX engineers concluded that virtually every one had functional shortcomings and was undesirably bulky and heavy. The direct result of that research was the creation of an innovative system that automatically and proactively distributes torque to all four wheels as needed. Called Variable Torque Management 4-wheel-drive (VTM-4®), this system provides front-wheel drive for dry-pavement cruising conditions and engages all-wheel drive when needed to improve stability or maneuverability. Unlike many competitive systems that use an engagement strategy triggered by wheel slippage, the MDX's VTM-4 system anticipates the need for all-wheel drive and engages the rear wheels before slippage begins.

Additional torque is redistributed to the rear for improved performance, especially on low friction surfaces. In addition, the VSA system provides a limited-slip differential effect by applying braking force to a slipping front wheel thereby directing driving force to the wheel with more grip.

Another special feature is a lock button, which temporarily holds engagement of the rear wheels to aid extraction from a slippery ditch or a snow bank.

To avoid the weight and bulk of a conventional transfer case, VTM-4's torque transfer unit is a compact cast-aluminum housing bolted directly to MDX's transaxle. Since this vehicle is engineered for medium-duty off-road capability, the transfer case is a single-speed permanently-engaged device without a low-range. Attached to the front wheel differential's ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case turn the drive ninety degrees, move it to the vehicle center line, and lower its axis by approximately 3.75-inches.

There are three distinct modes of VTM-4 engagement. The first - called the acceleration torque control (ATC) mode - is unique to this system. It works even on dry pavement to proactively distribute driving torque to all four wheels as the MDX accelerates from a stop to cruising speed. One notable benefit of this mode is that traction is immediately available to move the vehicle from rest through a slippery intersection before slippage occurs. (Once a wheel slips, the traction available for forward propulsion and lateral restraint is significantly diminished.) A second advantage is that apportioning drive torque among all four wheels greatly diminishes the likelihood of torque steer. Handling dynamics are also improved. Reducing the propulsive force carried by the front tires leaves more adhesion for steering the vehicle into a tight bend or for holding cornering arc in the middle of a turn. In other words, the MDX's dynamic balance is greatly enhanced by ATC logic.

Rear wheel torque rises smoothly from zero to the maximum setting in proportion to vehicle acceleration (both forward and reverse). At higher speeds, the front wheels are capable of providing the desired thrust with excellent handling so torque delivered to the rear wheels automatically diminishes with speed. While cruising, all driving torque is delivered by the front wheels in the interests of smoothness, quietness, and fuel efficiency.

The second engagement mode uses wheel slippage control logic. If the difference in rotational speed between front and rear wheels rises because of a slippery surface or poor traction at the front of the vehicle, that condition is detected by wheel-speed sensors which are monitored by VTM-4's ECU. In response, the ECU commands an increasing amount of torque for the rear wheels. Torque is proportional to both slip rate and the rate at which the slip rate is increasing. This operation is similar to conventional slip-based all-wheel-drive systems already on the market.

The third mode of all-wheel-drive engagement activates when the driver presses the lock button mounted on the instrument panel. The maximum amount of rear-drive torque is locked in until the vehicle gets moving and exceeds six mph, at which time rear drive torque is gradually diminished. By 18 mph, the lock mode is fully disengaged. When vehicle speed drops below 18 mph, the lock mode automatically reengages. The shift lever must be in the first, second, or reverse-gear position to use the lock mode.

The maximum torque delivered to the rear wheels is sufficient to climb the steepest grade observed on any public road in America - 31 degrees (60-percent slope) - with a two-passenger load on board. The MDX will also move from rest up a 28-degree (53-percent slope) dirt grade. On a split-friction grade (different amounts of traction at each wheel), VTM-4 automatically provides sufficient rear-wheel torque to help the vehicle climb a steep, slippery driveway to enter a garage.

Propeller Shaft and Half-Shafts

The two-piece propeller shaft that carries drive torque from the transfer case to the rear-drive unit is made of high-strength steel tubing to permit a smaller diameter, thereby improving both ground clearance and interior room. The cross yokes attached at each end by friction welding are forged steel for high strength and low weight. The center support bearing is rubber isolated to block the transmission of driveline noise from the interior of the vehicle. A low-friction plunger joint located near the center of the propeller shaft accommodates relative motion between front- and rear-mounted driveline components. A tuned-mass damper inside the front portion of the propeller shaft cancels any bending tendency in response to powertrain vibrations.

Equal-length, front-wheel half-shafts have a plunger joint at their inboard end and a ball-type universal joint at the wheel end. Rear half-shafts are similar in design but use a double-offset joint at the inboard end and a ball joint at the outboard end. All universal joints are constant-velocity type.

Rear Axle Drive Unit

The MDX's rear final-drive unit does not use a conventional differential. Instead, a hypoid ring-and-pinion gear set supported by a cast-aluminum housing switches torque from the propeller shaft's longitudinal orientation to the lateral orientation necessary to drive the rear wheels. Surface grinding the ring and pinion gear teeth yields the quiet operation expected of a luxury SUV wearing an Acura nameplate.

A connection from the ring gear to each wheel's half-shaft is made by left- and right-side clutches. Each drive clutch consists of three elements: an electromagnetic coil, a ball-cam device, and a set of 19 wet clutch plates which are similar in design to clutches used in an automatic transmission. Ten of the plates are splined (mechanically connected) to the ring gear while nine of the plates are splined to a half shaft. Left and right clutches are identical.

The VTM-4 system's electronic control unit (ECU) determines torque which is to be distributed to the rear wheels, then electric current is sent to the two electromagnetic coils. The resulting magnetic field moves a rotating steel plate toward each fixed coil. Friction between that steel plate and an adjoining cam plate causes the cam plate to begin turning. As it does, three balls per clutch roll up curved ramps, creating an axial thrust against a clutch-engagement plate. This thrust force compresses the wet clutch plates, thereby engaging drive to the corresponding rear wheel.

Unlike mechanically actuated four-wheel drive systems, the VTM-4 system is infinitely variable. The amount of torque provided to the rear wheels is directly proportional to the electric current sent from the ECU and can be adjusted from zero to a preset maximum. This current constantly changes to deliver the optimum rear torque calculated by the ECU. An internal gear pump circulates VTM-4 fluid to cool and lubricate the clutches, bearings, and gears within the rear drive unit. Use of high-strength, low-weight materials - such as die-cast aluminum for the housing - minimizes the bulk and weight of this hardware, helping to keep the weight of the entire all-wheel-drive system to about 212-pounds.

2006 Acura MDX - Chassis

Introduction

The Acura MDX was the first product in what has proven to be a very popular portion of the market: a car-like, family-sized, luxury SUV. To venture beyond current competitive offerings with a no-compromise design, a new chassis was essential. Engineered to deliver the exhilarating driving experience and the outstanding vehicle dynamics expected of Acura products, MDX exceeds conventional SUV chassis design standards by a wide margin.

To provide the MDX with a smooth, refined, car-like ride, the MDX's suspension utilizes the following key design elements to meet its ambitious driving dynamics goals:

• Extra-wide track dimensions
• Short wheelbase for agility
• Rubber-isolated front and rear subframes
• Independent front and rear suspension systems with car-like geometry and long wheel travel for sporty handling and a comfortable ride
• 17-inch cast-aluminum flangeless wheels (Touring Package)
• All-season, radial tires with silica tread compound for excellent traction and fuel economy
• A Vehicle Stability Assist (VSA) system with active yaw control to integrate traction control, the VTM-4 system, Anti-lock braking, throttle control and stability control
• Four-wheel disc brakes with four-channel ABS, electronic brake distribution and Brake Assist
• Torque sensing rack-and-pinion power steering

Power Rack-and-Pinion Steering

MDX's steering system is tuned for quick, linear, car-like response and sensitive feel - and the torque sensing, power steering assist is high for parking maneuvers and low at highway speeds. As cornering forces rise, understeer is mild and linearly progressive to accentuate predictability.

This system has been tuned for optimal steering feel. The valve body incorporates a damper valve that improves steering feel at high speeds, and a kickback reduction valve that substantially reduces steering kickback when encountering bumps or objects in the road or trail. A roller bearing in the steering shaft makes steering easier in parking situations.

Front Suspension

The front suspension provides an incredibly smooth ride without compromising the MDX's nimble handling. The shock absorber units feature NWS (New Wide Setting) damper valves, which are designed to reduce low speed compression damping 10 percent and rebound damping by 30 percent while increasing high speed damping by 30 percent.

MDX has a wide track - 66.3-inches front, 66.5-inches rear - to optimize handling precision, stability, and ride comfort. The strut-type front suspension provides a generous 7.3 inches of wheel travel (4.3-inches in compression, 3.0-inches in rebound) with a moderate spring rate and relatively firm damping. Separate load paths to the unit body are provided for the coil spring and the shock absorber to facilitate tuning out road noise. A solid 0.9-inch stabilizer bar is linked directly to the strut via ball-joint connections to resist body roll during cornering maneuvers. The small 0.04-inch scrub radius designed into the front suspension is unusual for SUVs but this feature gives the MDX car-like steering response and handling that's consistent and predictable in on- and off-road situations. Accelerating or hard braking with uneven traction underfoot does not cause MDX to drift off line as is the case with many SUVs.

A low roll center (6.2-inches above the ground) further improves MDX's handling precision. The lower control arm bushings are designed to provide a stabilizing toe-out steering effect when loaded during braking or cornering. The L-shaped arm allows a very tight steering lock for good low-speed maneuverability. In fact, the Acura MDX's turn-circle diameter is a modest 37.2 feet.

Front Subframe and Mounting Systems

The MDX's engine, transaxle, transfer case, steering gear, and front suspension are all supported by a welded-steel subframe secured to the unit body's longitudinal rails through four tuned rubber isolation mounts. The front of the subframe assembly is tubular for maximum stiffness with minimal weight. A stiffener located under each subframe attachment fastener helps stabilize the assembly, thereby sharpening handling and braking performance. A stiffener plate bolted across the subframe under the transfer case greatly increases the assembly's rigidity. Two dynamic dampers and one mass damper are positioned to counteract noise and vibration, while two fluid-filled engine mounts quell vibration at idle and isolate powertrain NVH from the passenger compartment. The steering gear mounts are made of heat-resistant rubber to provide good vibration isolation, the firm retention necessary for sensitive on-center-steering feel, and life-of-the-vehicle durability.

Rear Suspension

Like the front suspension, the rear suspension has also been tuned for a smooth, refined ride for each passenger position. The rear spring rate and damping were configured to reduce low speed compression damping and rebound damping while increasing high speed compression and rebound damping. To ensure more precise damping control throughout the entire range of the suspension system, the twin-tube, gas filled hydraulic shocks also feature New Wide Setting (NWS) damper valves.

The MDX's rear suspension is a compact, multi-link trailing arm layout for excellent ride and handling, light weight, and optimum packaging. Wheel travel is a generous 4.9 inches in compression and 3.3-inches in rebound. The three links that position each rear wheel laterally run between the knuckle assembly and the subframe. A trailing arm also runs from the unit body to each rear knuckle. Coil springs sit on the lowermost lateral link and anchor against the unit body directly behind each axle shaft. Shock absorbers, positioned ahead of the drive shafts, run from a low point on each knuckle to a secure attachment point on the unit body. Knuckles are an "in-wheel" design to optimize suspension geometry and packaging efficiency. Bushing compliance provides a modest toe-in effect in response to substantial cornering and braking loads to enhance dynamic stability. A solid 0.8-inch anti-roll bar helps keep the body relatively flat during hard cornering. The rear roll center is positioned at a 6.7-inch height to provide linear and predictable behavior at the limit of adhesion. The results speak for themselves, as MDX truly sets the standard for ride and handling in the luxury SUV category.

Rear Subframe

The packaging of major components at the rear of the MDX is a major engineering challenge. The rear subframe, which supports most of the rear suspension and the rear axle drive unit, is made of high-strength steel for high stiffness and minimal weight. A rear subframe stay helps maintain precise positioning of the rear suspension and provides improved handling precision. The shape of the rear subframe is very important since it must accommodate the drivetrain components for the VTM-4 four-wheel drive system and the multi-link rear suspension pieces while still enabling the versatility of the third-row seat and flat cargo floor. For excellent ride and handling characteristics, the subframe attaches to the unit body at four widely spaced, rubber-isolated mounting points. Rear-suspension components, especially the springs and shock absorbers, are as compact as possible to facilitate a wide, flat load floor and to leave room for both a spare tire and a full-size fuel tank. The rear axle drive unit is mounted to the subframe by means of rubber isolators to block road and powertrain noise and vibration from the passenger compartment. A tuned dynamic damper attached to the drive unit cancels propeller-shaft and drive-shaft vibration.

Wheels and Tires

The MDX and the MDX with Touring Package are fitted with die-cast flangeless aluminum wheels. Both have 6.5-inch-wide by 17-inch diameter rims, a 45mm offset dimension, and a five-lug bolt pattern. The flangeless wheels provide a flush, integrated look. Large openings in the wheels provide ample brake-system ventilation. Tires supplied by Michelin and Goodyear are both sized P235/65R-17 and carry an M+S (mud and snow) label and a T (118 mph) speed rating. Both the tread and the internal construction were designed with computer-aided tools to achieve excellent ride comfort, low noise and wear, and best-in-class all-weather performance. Tread materials are compounded for excellent winter traction and low rolling resistance. During initial cold weather engineering tests, the MDX's tires consistently outperformed some of the most highly rated snow tires on the market.

The compact spare tire is carried under the load floor near the center of the vehicle and can be lowered by turning a hidden hex-head bolt with the provided lug-nut wrench. The hex-head bolt is located under a cover conveniently located in the rear hatch trim area. This arrangement guarantees the security of the spare and keeps it readily accessible while allowing enough space for the revised exhaust system. This configuration also allows access to the spare tire without disturbing luggage or cargo carried onboard. Room is provided to stow a flat or a full-size spare in the compact spare's location. Corrosion and failure of spare tire retention equipment, a common problem in some competitor SUVs, is avoided by use of stainless steel and polymer materials eliminating high-mileage failure.

Tire Pressure Monitoring System

The MDX features a direct Tire Pressure Monitoring System (TPMS). Using a series of four sensors and four initiators (one for each tire) and a receiver to capture and relay information, the system alerts the driver when it detects that tire pressure in one or more tires drops significantly below the recommended pressure.

The sensor transmitter is located inside the wheel. Should the tires be rotated around the vehicle due to normal maintenance or be replaced entirely, the new tires are "auto-located" by the system. If the system detects that tire pressure is significantly low (32 psi is recommended), a low tire pressure indicator located in the meter containing the fuel level and temperature gauge will come on while a schematic of the vehicle located in the center meter housing the speedometer will indicate which tires are low.

Braking System

The MDX is equipped with state-of-the-art, four-wheel disc brakes and a four-channel Braking System. The brake system hardware is tuned for quick response, low effort, and short pedal travel. For optimum performance with widely varying loads - including the possibility of towing - the MDX features an innovative Electronic Brake Distribution system (EBD). Brake Assist helps with the brake function during accident avoidance maneuvers. At the rear, a select-low braking strategy is used to preserve directional stability in slippery driving. In the event one rear wheel verges on lock-up, triggering a pressure modulation at that wheel, brake pressure is also diminished at the adjoining wheel to preserve lateral stability.

Extra-large brake rotors and calipers provide the capacity necessary for short stopping distances and excellent fade resistance - even with a heavy load in tow - and the precise pedal feel expected of an Acura. The vented front rotors are 11.8-inches in diameter and 1.1-inches thick. Solid drum-in-disc rear rotors are 12.3-inches in diameter and 0.43-inch thick. The MDX features dual-piston calipers on the front wheels for even more secure stopping. A drum-type parking brake mechanism is positioned within the inner portion of the rear rotor. Parking brakes are both set and released by stepping on a pedal, freeing space in the console area. The compact tandem-type vacuum booster consists of two 9-inch diameter booster chambers.

Anti-Lock Braking System (ABS)

MDX brake components are large in capacity to help handle heavy loads - both those carried on board and those towed behind. Front-to-rear brake effort proportioning is electronically regulated. The Anti-lock Braking System (ABS) has four sensing and activating channels to detect a wheel on the verge of lock up. In the event this occurs, brake pressure is held, then reduced, to permit that wheel to regain traction before full braking resumes. A select-low strategy controls the braking effort at both rear wheels as soon as one nears lock up to safeguard lateral adhesion and to help avoid any tendency to spin or fishtail during hard braking.

Brake Assist

Brake Assist helps drivers apply full braking pressure in an accident avoidance situation. To do so, a microprocessor continually analyzes and "learns" the driver's normal braking habits.

In an emergency braking situation when the brakes are suddenly applied but inadvertently released by the driver to avoid wheel lockup and then reapplied, brake assist helps the driver apply full braking force via the ABS actuator. A pressure sensor detects an increase in brake fluid pressure and activates the ABS system. Braking pressure is maintained momentarily after the driver's initial braking action to help the driver stop promptly.

Importantly, Brake Assist assists the driver in obtaining full braking performance in an emergency. The Brake Assist system deactivates when the driver releases pressure on the brake pedal.

Vechicle Stability Assist (VSA)

For enhanced control during acceleration, cornering, and sudden collision-avoidance maneuvers, the MDX is equipped with a standard 4-channel Vehicle Stability Assist (VSA) system that works in conjunction with the VTM-4, drive-by-wire throttle and ABS systems. This system contains sensor logic to provide active yaw control to help provide even more secure footing. Active yaw control helps the MDX follow the cornering line intended (by the driver) more faithfully and naturally, greatly enhancing its stability.

The VSA system enhances vehicle stability by applying brake force to each of the MDX's four disc brakes independently while also managing the throttle and ignition systems. An additional benefit is the limited-slip differential effect the system provides for the front wheels by applying braking force to a slipping wheel thereby redirecting driving force to the wheel with more traction.

Analyzing data that is constantly received from eight vehicle sensors monitoring speed, steering input and lateral G forces, the VSA system compares the driver's control inputs with the vehicle's actual response. If the actual response is outside a predicted response range - as can happen when cornering forces exceed the tires' performance capabilities - VSA automatically intervenes with an appropriate corrective action. In the case of oversteer, VSA applies braking to the outside front and rear wheels to counter the unintended yawing effect. If understeer is detected, VSA applies braking to the inside front and rear wheels and reduces engine power to help bring the car back onto the driver's intended course.

The VSA system in the MDX has been carefully calibrated to add handling stability and predictability without intruding on the process of spirited driving. Whenever the system is actively enhancing the vehicle's stability, an indicator light flashes on the instrument panel. In addition, VSA's stability enhancement and traction control can be turned off with a cockpit switch while still leaving the Anti-lock Braking System fully functional.

Fuel System

The MDX fuel tank reduces sloshing noise, has a driving range by 23 miles and helps to meet LEV-2 Evaporative emission standards. The tank is molded of high-density polyethylene for low weight, freedom from corrosion, and impact resistance. It's positioned immediately ahead of the rear wheels and over the propeller shaft to help guard against collision damage. Corners of the tank are rounded and the inside of the tank is baffled to diminish the likelihood of sloshing-fuel noise. The polyethylene filler pipe and fuel lines are light, not susceptible to corrosion, and resistant to fuel vapor losses. A high-efficiency fuel pump is housed inside the fuel tank. The fuel-filter is a lifetime design that never needs maintenance.

MDX complies with all evaporative emissions, on-board diagnostics, and refueling vapor recovery requirements. The fuel vapor canister and filter are rubber mounted for noise isolation and protected against rock and debris damage by a deflection shield.

Towing

The ability to haul pop-up campers, medium-sized boats, and recreational vehicle trailers is high on the priority list for many SUV owners. To understand this aspect of the MDX's makeup, MDX engineers polled focus groups and studied survey results that tapped 200,000 households. Their findings offered the insights needed to properly outfit the MDX to surpass the towing expectations of most customers. Engineers learned that roughly one third of the six-cylinder-powered-SUV owners expect to tow something at one time or another. In addition, 18-percent tow more than four times per year. Approximately 10 percent of the miles accumulated on six-cylinder SUVs are with a trailer in tow.

Another notable discovery was that many customers aren't particularly knowledgeable about towing technicalities. Terms like "gross axle weight" may be germane to the engineering process but such language can leave average customers in a state of bewilderment. This realization

convinced engineers that customers' interests are best served by load ratings that are both realistic and easy to comprehend. Ultimately, the engineers concluded that a casual or weekend towing capability was most appropriate for MDX. Customer feedback helped set the towing limit at 4500 pounds for boats and 3500 pounds for other types of trailers. A heavier load is acceptable with boats because their pointed bow shapes impose less aerodynamic drag on the towing vehicle than a slab-faced, square-cornered trailer.

Industry practice is to boast a high maximum tow rating, even though some sacrifice of passengers and cargo may be necessary to suitably accommodate such a trailer load - in some cases limiting the vehicle to one passenger to accommodate the maximum specified towing capacity. The Acura MDX's 3500/4500-pound rating is calculated to include up to four passengers and their cargo.

To help ensure that customers will be able to move a maximum-rated load up a grade from rest (such as pulling a loaded boat trailer up a launch ramp), engineers sought out the most challenging entry roads and launch ramps in the country. Through testing, they verified that MDX proficiently handles the 17-degree (31-percent) grades on mountain roads approaching Lake Cumberland in southern Kentucky and the strenuous combination of 15-degree (27-percent) grades and 5280-foot elevation at Lake Tahoe. At sea level, MDX can move a 4500-pound boat and four passengers up an 18-degree (32-percent) slope. A note in the MDX owner's manual suggests reducing gross combined weight two-percent for every 1000 feet of elevation.

In support of safe towing, MDX's tow hitch and other hardware needed for the job are factory engineered for dealer installation. The dealer-installed trailer hitch is a Class III receiver-type design that bolts on with no drilling, cutting, or bumper-cover modifications. An external transmission cooler and a separate power-steering fluid cooler is also included along with a harness to provide electrical power to trailer lights plugs into a connector provided at the rear of the vehicle.

2006 Acura MDX - Body/Interior

Introduction

To pursue a new direction in the luxury SUV segment, Acura designed the MDX as the first SUV to combine a car-like ride and handling with a family-sized SUV interior. By avoiding some of the compromises that other manufacturers have accepted, MDX combines dynamic performance, utility and luxurious accommodations with the value expected of all Acura vehicles. The MDX concept rests on these four fundamental principles:

• Interior and exterior designs that are consistent with Acura philosophies of intelligent design, elegant styling, thoughtful features, packaging efficiency and high value
• Exterior styling that subtly expresses the vehicle's athleticism and complements the surprising flexibility and functionality of the interior
• The versatility to quickly and easily adapt the interior space to a variety of useful and practical layouts that reflect the varied and often contradictory needs of SUV buyers
• Well-balanced vehicle dynamics to reward the driver with a feeling of exhilaration during sporty driving, the capability for medium-duty off-road driving, the competence needed to conquer winter conditions and the power required for towing

Exterior Design

The Acura MDX design concept was born at Honda's R&D facilities in Torrance, California. Designers selected the freedom of the Southwest as a conceptual theme for the exterior design. MDX is purposely different from conventional SUVs - a theme that carried through from the very initial stages of development.

The MDX adopted a clean, strong and elegant exterior design to complement a functional and versatile interior space. The lines create a natural flow from front to rear, as if MDX was sculpted from one solid piece, reinforcing the sense of strength and ruggedness. The individual surfaces of the hood, fenders and doors are finely sculpted with detailed character lines that are both attractive and functional - simultaneously strengthening the panels and managing airflow over MDX's aerodynamically efficient shape.

The solid front is anchored by the familiar pentagonal Acura grille, and continues with an intricately detailed greenhouse area that culminates in a D-pillar that sweeps gently forward. This D-pillar design is important to the overall shape of MDX - it finishes the look of this finely sculpted shape while providing a functional design for MDX's rear liftgate. Form and function work hand-in-hand as the forward upper edge of the liftgate allows the rear hatch to open with minimum clearance required behind the vehicle. This simplicity and elegance of design is a metaphor for MDX as a whole - each design element has been carefully thought out to produce a vehicle that is as pleasing to the eye as it is to drive.

To make this product a significant leap forward in environmental awareness and, ultimately, the intelligent SUV choice for sophisticated buyers, MDX designers shaped the vehicle's exterior to minimize aerodynamic drag and specified the use of recycled materials where possible. The aerodynamically efficient shape results in low wind noise and improves highway fuel economy for this environmentally conscious vehicle.

MDX designers mapped out a fresh set of proportions to meet these development goals, incorporating a full-size interior into a mid-size SUV's exterior space. That meant stretching exterior width to maximize the available interior space and benefit dynamic stability. They made the cabin as long as possible in the interests of interior roominess. They selected a short hood and a strong frontal appearance and they shaped the vehicle's corners to refine MDX's aerodynamic performance. To enhance off-road capability, they specified a high ground clearance but also provided a low door opening to ease entry and egress. In the side view, the body-to-glass proportion was optimized for a sporty demeanor. Windows were maximized for excellent outward visibility.

Body Structure

MDX's body structure meets rigorous design requirements. Several advanced unit body concepts have been applied to yield a structure with outstanding levels of occupant protection. High rigidity is another top priority. A stiff structure is essential to achieving balanced and predictable handling and assuring that the ride is smooth and quiet for the life of the vehicle. High levels of torsional rigidity help provide the MDX with precise handling by minimizing any unwanted movement of suspension components and changes in geometry.

Reducing weight is a key to the well-rounded performance demanded of MDX - dictating the use of high-tensile steel in many critical areas. To achieve their high goals for safety and performance, MDX engineers used powerful computer simulation and analysis tools to optimize body design and conduct virtual collisions before the first prototypes were even constructed.

To meet the MDX's ambitious strength, stiffness, and weight targets, body engineers selected a unit body design with rubber-isolated front and rear subframes. The high level of bending and torsional rigidity designed into the MDX body structure helps improve handling precision by providing a rigid platform for mounting the suspension components.

Like all Acura products, MDX's body is designed to deform progressively in front, side and rear collisions. Engineering front, side and rear sections that help absorb the energy of a collision reduces the likelihood of occupant injury. A highly rigid passenger section is reinforced laterally and longitudinally to maintain its size and shape for omnidirectional protection.

Much of the MDX's rigidity and resiliency comes from its robust floor construction. Two longitudinal rails run the length of the vehicle, from bumper to bumper. These rails are buttressed by a total of eight box-section crossmembers at critical points along the vehicle's platform and further reinforced by two bumper bulkheads. This provides the strength needed to resist standard barrier impacts at the front and rear, offset crashes, and side impacts. Additionally, both the rear floor and wheel house are reinforced for increased rigidity.

A passenger compartment safety shell design is used to protect occupants with structural "rings" at the A, B, C, and D pillars that run continuously around the circumference of the vehicle to help minimize intrusion during side impacts. Reinforced steel stiffeners inside the doors at the beltline provide a continuous horizontal connection between the first three pillars. High tensile-strength steel tubular beams inside the door structure at wheel height provide additional intrusion resistance. A single-piece side-ring design is used to assure tight and consistent fit and finish in the critical closure areas (doors and windows), and the doors are made using laser-welded tailored blanks. This innovative door design uses higher-gauge steel in high-stress areas and lighter gauge steel in other areas to save weight yet maintain structural integrity for durability and safety. About one quarter of MDX's steel body parts are high-tensile steel. Longitudinal rails, floor crossmembers, and pillar reinforcements that carry heavy loads are made of the stronger heavier gauge steel. A roof-mounted reinforcement is provided to secure the center passenger's upper-shoulder belt.

One of the toughest challenges facing an SUV body-structure engineer is achieving adequate stiffness in the rear hatch opening. Reinforcements placed on the right and left of the tailgate opening enhance body rigidity even further. The use of high-strength, closed-section steel bumper beams enhances occupant safety and decreases damage sustained during rear end collisions.

All this works together to make the 2006 MDX one of the safest SUVs on the road. In recent front passenger, side passenger and side impact crash tests conducted by the National Highway Traffic Safety Administration (NHTSA), the MDX achieved the top rating of "five star" in all three categories.

Aerodynamic Design

A low aerodynamic drag coefficient was essential to achieving MDX's goal of outstanding highway fuel efficiency. Toward that end, MDX was styled with a sloped and tapered front-end. The windshield, which now features acoustic glass, is tilted at a low angle to help air flow smoothly over the roof. At the trailing edge of the roof, a tapered surface minimizes wake turbulence. A chin spoiler integrated below the front bumper deflects air to the sides that would otherwise flow under the vehicle. A strake (air deflector) is also positioned ahead of each front tire to direct air to the smooth sides of the vehicle. The coefficient of drag of the MDX is 0.36. As a result, highway fuel efficiency is an impressive 23 mpg.

Lamp Design

Front-of-vehicle illumination is integrated into attractive and aggressively styled projector-type halogen lamp assemblies that offer better superior illumination. Following the lines of the grille, the redesigned lamp assemblies wrap around to the forward edge of the front fenders, providing a natural transition from the vehicle's front to its side. A clear outer lens provides a clean look and allows smooth air flow around the vehicle's front corners. The innermost lamp is for high-beam illumination and uses a rectangular reflector. In the middle position, a projector-style, circular-shaped low beam provides for excellent near-vehicle illumination. Twin amber stripe parking and turn signal lights occupy the outermost position of the lamp assembly.

Fog lamps are standard MDX equipment. For a consistent appearance, a clear lens and a multi-faceted reflector are used for this lamp. The fog lamps are positioned just below the bumper surface adjacent to the lower air intake.

The taillight assembly features a sophisticated design. The direction signals are separated from the back-up lamps and are located at the top of the assembly. The dark chrome upper bucket surrounding the bulb matches the look of the headlights, providing a uniform look. The isolated reverse lights with circular reflectors remain in their central position, dividing the combination stop/tail-lamp display, which has been lowered slightly to provide a sportier look. The reflector keeps its position at the bottom edge of the assembly.

Glass

Excellent visibility, giving drivers a commanding view of the road ahead and passengers a pleasant open feeling, was a high priority in designing the MDX. To that end, MDX provides an outstanding 286 degrees of outward visibility.

To control the migration of water over the front door glass, windshield side moldings were extended to create a dam that helps channel rain and sleet up and over the roof. Squaring the rear edge of the outside rearview mirror's mounting base benefits air flow patterns and reduces wind noise.

Acoustically Tuned Glass Windshield

To reduce noise in the cabin the windshield is made of 4.7 mm thick acoustic glass, which consists of two layers of safety glass, separated by a thin acoustic resin center. The windshield reduces road noise on smooth asphalt significantly in the higher frequency ranges.

Door Design

Many SUVs have plastic cladding on their lower body surfaces. A damage analysis study by MDX engineers revealed that cladding positioned low on the side of the vehicle actually offers little protection from parking lot and garage scarring because contact is far more likely to occur at the mid-point of the door or higher. For this reason, and in the interests of providing customers with a clean, strong, and elegant appearance, MDX is not equipped with side-surface cladding.

Another discovery was that dirt and mud can build up on vertical sill surfaces below the door seals. This is an annoyance because the dirt often soils pants, dresses or other clothes as occupants enter the vehicle. To avoid this problem, an extra seal has been included at the lower interior edge of each door. These seals rest against the side sill garnish and block the build up of dirt and debris, helping to ensure clean and hassle-free entry and egress - no matter what outside conditions might provide.

Special measures have been taken to make MDX highly resistant to intrusion by thieves and vandals. The liftgate is not equipped with an exterior lock cylinder and can only be unlocked with either a remote key fob or the interior switch. Reinforced steel guards have been installed to deflect break-in tools away from the front door lock rod and latch mechanism. Double thick steel around the driver's door key cylinder stops vandals from prying their way into the vehicle - and for added security only the driver's door is equipped with a traditional key-lock cylinder.

The window sashes are equipped with continuous window frame guides that completely surround the door glass and limit access through this sometimes vulnerable area of the vehicle. Rear lock rods are positioned behind the center sashes so they are inaccessible from outside the vehicle.

Auto On/Off Headlights

The MDX is equipped with auto on/off headlights. A sensor at the front of the instrument panel senses outside illumination levels; when darkness occurs during automatic mode, the headlights, taillights, and instrument panel lighting turn on automatically for nighttime convenience. When the vehicle is parked at night, the lights remain lit after the ignition switch is turned off, but extinguish automatically when the driver's door is opened.

Side Mirrors

The MDX features "diffuser" side mirrors that smoothly channel air between the mirror and the side window glass resulting in less wind noise and improved aerodynamics. A layer of Thinsulate further reduces wind noise.

The use of blue-tinted side mirror glass greatly reduces sun and headlamp glare to the driver. Owners of the MDX with optional Touring Package receive two keyless remote key fob units that can be pre-programmed so the mirror (and driver's seat) settings automatically match the memory settings of that particular driver.

The MDX Touring Package adds another handy feature - when the transmission is shifted into reverse, the right-side mirror angles down 15 degrees for better visibility near the vehicle. Moving the power mirror adjuster switch out of the center position can disable this feature. MDX engineers provided electrical heating to the outside mirrors not only to defog them in winter but also to reduce the likelihood their surfaces will be damaged by contact with ice scrapers.

Washer and Wiper Systems

As part of the MDX's "defeat winter" goal, engineers invested extra effort in the vehicle's window washer and wiper systems. The MDX with Touring Package features rain-sensing front windshield wipers that, when in the "automatic" position, adjust wiper speed depending on the amount of rain that is falling on the windshield. A sensor located on the windshield behind the rearview mirror monitors the amount of rain on the windshield and adjusts wiper speed accordingly. For individual preference, the driver can select either of two pre-set wiper speeds.

The rear wiper arm is a clean, one-piece design. A spray-type increases water flow for a quicker and more thorough rear-window cleaning. Fluid is delivered almost the instant the wash button is touched thanks to a check valve in the delivery line.

Single-piece wiper arms are used on the front windows. Fluidic nozzles are fitted here for several reasons: they have a large orifice that covers more surface area, they are less likely to clog than a conventional nozzle and they clean the windshield with fewer wash cycles.

Roof Rack

Designed to accentuate both the styling and utility of the MDX, the integrated design of the roof rack (standard on the MDX with Touring Package and available as an option on the MDX) consists of two fixed cross bars that mount in the rain channel of the roof. The cross bars are designed to carry items weighing up to 150 pounds when properly loaded. Engineers optimized the location of the bars for loading convenience and the roof rack crossbars have an airfoil-shaped cross-section to avoid wind noise. They are made of plastic-sheathed steel for high stiffness and durability. The adjustable end stays are sturdy zinc die-castings covered with stylish trim. Accessory components are offered to facilitate transporting skis and bicycles or a variety of other items.

Antennas

The MDX features a powered, active glass antenna in the rear window. Antennae for the Acura Navigation System with Voice Recognition, OnStar and XM Satellite Radio are located on the rear portion of the roof.

Spare Wheel and Tire

A compact spare tire is carried under the rear load floor and can be lowered by turning a hex-head mounting bolt with the provided lug-wrench. The mounting bolt is neatly concealed under a cover conveniently located inside the rear hatch trim area. This arrangement guarantees the security of the spare and keeps it readily accessible without disturbing luggage or cargo carried onboard. Room is provided to stow a flat or a full-size spare in the compact spare's location. All spare tire mountings and hardware are made of stainless steel and polymer materials to minimize corrosion.

Moonroof Wind Deflector

Wind noise can be annoying when the sunroof is open in a vehicle with a large interior volume. MDX engineers solved this problem by providing a wind deflector that automatically rises into the air stream when the glass moonroof is opened. An aluminum blade and composite end pieces are used to save weight. As a result of the wind deflector, the MDX is one of the quietest SUVs on the market with the moonroof in either the open or closed position.

Exterior Colors

The 2006 MDX comes in the following exterior colors: Taffeta White, Aspen White Pearl, Starlight Silver Metallic, Sandstone Metallic, Midnight Blue Pearl, Nighthawk Black Pearl, Burnished Bronze Metallic, Redrock Pearl, Desert Rock Metallic, Billet Silver Metallic, and Steel Blue Metallic. The new exterior color for 2006 is Amazon Green Metallic, which replaces Sage Brush Pearl.

Interior Design

In the MDX, clean, solid forms on the instrument panel and door areas define a wide open and luxurious space. Positioned within that space are the driver's cockpit and a multi-use console reminiscent of other Acura models. Wood-patterned panels, chrome accents and the generous use of leather trim complement the design.

For 2006, strategic enhancements were made to the interior of the MDX designed to further raise the level of style, comfort and refinement. Upgrades include the use of luxurious ebony-colored Zebra wood on key accent points. In addition, Satin Chrome interior accents are added on models equipped with the Touring Package, giving the interior an even more upscale feel.

The focal point of the instrument panel is the personal computer aspect of the center control panel for climate control, music system, trip computer and, in the MDX with Touring Package, the available next-generation Acura Navigation System with Voice Recognition and Acura DVD Entertainment System. The console storage compartment offers a wealth of functional features without diminishing the overall sense of roominess.

Control switches, beverage holders, storage pockets, power outlets, and audio speakers are located throughout the interior to offer a remarkable degree of ergonomic functionality while upholding the desired clean, purposeful theme. Seats are designed with a luxurious, stylish appearance and a sporty image consistent with this product's athletic driving attributes.

Front and side airbags for the driver and front seat passenger are standard, as are a headrest and 3-point safety belts for all seven passenger seating positions. For added safety of front seat occupants, weight sensors are incorporated in the front passenger seat to determine the total weight on the passenger seat. If it is less than 65 pounds (as if occupied by a small child or car seat) the front airbag will not deploy. For the driver, a position sensor in the seat is used to determine how the airbag will be deployed in the event of a collision. If the seat is within half an inch of the most forward position, the front airbag will only deploy in the dual-stage mode. If the seat is farther than a half inch from the forward position, the airbag deploys in either single or dual-stage mode based on the severity of the collision.

A roof-mounted Side Curtain Airbag System protects all three rows of occupants, which is standard equipment on all MDX models. The side curtain airbags deploy from a module in the roof in the event of a sufficient side impact, providing an important and significant level of head protection in the window area. Should the MDX begin to tip, a roll angle sensor along with lateral G and transverse G sensors, located just in front of the windshield determine the rate of roll and deploy the side airbags accordingly.

In the interest of versatility, second- and third-row seats were designed for easy configuration from seven-passenger vehicle to cargo vehicle with a flat cargo floor - or any layout between the two extremes. And to make the most use of the interior volume, an under-floor storage compartment is also provided behind the third row of seats.

The Acura MDX's interior provides more seating and cargo space than any of its key luxury SUV competitors - without resulting in a bulky exterior. This was achieved by taking advantage of its extra-wide wheel-track dimensions and an innovative driveline that delivers robust power, performance, and all-wheel-drive traction without intruding on interior space. MDX's interior has a low, flat floor for the first- and second-row seating positions for easy entry and egress. The lack of a large and intrusive driveshaft tunnel and unwieldy rear-axle intrusion yields room for up to seven passengers in three seating rows, a highly versatile center console, and a cargo area wide enough to accept four-foot-wide sheets of building materials.

In keeping with Acura's tradition of selling fully-featured products, MDX offers a wealth of power accessories, conveniences, and refinements as standard equipment. The MDX was the world's first SUV with a synchronized front and rear climate control system engineered for rapid warm-up in cold weather, expedient cool-down during summer months, and maximum all-around comfort for all seven passengers.

The center console is designed to provide a front-seat armrest, a handy storage compartment, and second-row-passenger's serving tray. A large central LCD display screen houses the standard multi-function trip computer and in MDX models equipped with the optional Touring Package, the available DVD-based satellite-linked Acura Navigation System with Voice Recognition and Acura DVD Entertainment System. Climate-control buttons and displays are also integrated within the display screen for easy access, viewing and operation. Both the standard system and the Acura/Bose® music system play AM/FM/CD, XM® Satellite Radio and cassette source material. The premium 225-watt Acura Bose® music system, features an in-dash, six-CD changer on all models, employs an additional 8-inch speaker.

MDX's steering wheel uses a thick rim section for a sporty, substantial feel. The leather cover is perforated in grip areas to prevent slippage. Cruise control switches are positioned between the right-side spokes while the music system control switches are in a corresponding position on the left. Models equipped with the Acura Navigation System with Voice Recognition, voice recognition controls are also located on the steering wheel.
The transmission shift lever is trimmed in wood and leather. The shift lever moves through a gate that helps the driver quickly find the desired gear position. The center panels of the leather seating surfaces are also perforated to provide additional ventilation.

Seven-Passenger Seating Accomodation

Three-row seating - two bucket seats in front, a three-passenger, 60-40-split middle-row bench seat, and a two-passenger 50-50-split bench seat in back - is standard. Leather-trim on seating surfaces for the front two rows is also standard. Third-row seats are upholstered in a leather-like, matching vinyl material for resistance to spills, dirt and scuffing.

The MDX features an eight-way power-adjustable driver's seat while the Touring Package adds a special power-adjustable lumbar support that flexes to match the natural curve of the spine under the weight of a passenger. Both the upper torso and the pelvis are held in an orthopedically correct position. The lower cushion design provides excellent comfort, even for larger occupants.

Side bolsters are configured to comfortably hold the driver during spirited driving without impeding ingress and egress. The relatively flat, open design of both front seats give the driver and front passenger the freedom to adjust seating positions easily for added comfort on long trips. Integrated headrests and electric heating elements are standard in both front seats. In MDX models with the Touring Package, memory seating positions - as well as the rearview mirror pre-sets - are matched to either one of the two keyless remote entry fobs, and automatically adjust to each driver's pre-selected positions.

The MDX's seats are extremely comfortable and ideal for everyday driving or long road trips. Soft, flexible leather cover the first and second row seats, which compliment the upscale interior throughout the cabin.

All seating positions have three-point seat belts. Front seat belts are equipped with pretensioners and automatic load limiters that are activated during severe frontal collisions. The MDX comes with standard front dual-stage, dual-threshold airbags. These airbags can deploy at the most appropriate of two rates - depending on the severity of the crash and seat belt use. Weight sensors on the front passenger side, a seat position sensor on the driver's side and deployment logic for the front airbags further enhance safety.

The driver's and front passenger's seats also feature side airbags mounted in the seat bolster closest to the door. The passenger's seat is equipped with a system designed to disable side air-bag deployment and help prevent injury to a child (or small-statured adult) if they lean into the side airbag deployment path. Once the occupant returns to an upright seating position, the side airbag will reactivate so it can deploy and help protect the passenger in a sufficient side impact.

Passengers in all three seating rows are protected by a Side Curtain Airbag system. The side curtain airbags deploy from a module in the roof in the event of a sufficient side impact, providing an important and significant level of head protection in the window area. In the unlikely event the MDX begin to tip, the sensors monitor the rate of roll and deploy the side curtain airbags accordingly.

MDX's middle-row seat is a 60-40-split design with comfortable room for three passengers, height-adjustable headrests, and a fold-down combination armrest and dual cupholder. To comfortably accommodate taller passengers, MDX engineers located seat height a reasonable distance above the flat floor and made the door openings larger for unrestricted entry.

Second-row seatbacks can be adjusted through seven positions of recline. The Lower Anchors and Tethers for Children (LATCH) system is included on outboard second row seats. The LATCH system features built-in anchors and ready-to-use tethers that allow compatible child safety seats to be installed without using the vehicle's seat belt system.

To fold the second row seat, a special four-bar linkage automatically cantilevers the bottom seat cushion both down and forward as the seat back is folded down to create a flat load floor. In contrast to some competitor's SUVs, releasing, lowering, raising, and re-latching the folding second-row seat are simple one-handed operations. Placing a child in the second row seating area or loading a grocery bag into the cargo through the back door are, thanks to design ingenuity, simple tasks.

The convenient walk-in feature provided at the right (curb) side of MDX's second-row seat makes entry and egress of the third row of seats easy and convenient. Lifting one lever permits the whole seat to slide forward on its tracks and the backrest to tilt forward, providing an entry path to the third row seats. Simply pushing the seat rearward again re-latches the seat in its rearmost position. The seat-tilt mechanism, step-in height, and the increased opening provided between the open second-row seat and the door frame are all sized for easy and convenient use by children. A hand-hold is also provided on MDX's rear side wall trim to simplify passenger access to the third row seats.

MDX's third row is an occasional seat configured specifically for children or small adults. A slightly elevated hip point height provides good forward visibility for third-row passengers while headrests are both height adjustable and removable. Like the second row, backrests can be reclined through six positions. Two tether anchors are provided for securing one or two tether-style child safety seats in the third row seats.

When not in use, either half of the third-row seat can be folded flat on a 4-bar linkage (similar to the second row seat) that brings it flush with the floor. Handles positioned at the top-outboard corners are accessible both from the rear doors and from the tailgate. This lift handle also releases each half of the seat so it can be raised or lowered independently. The third-row seat headrests can be stored in the cargo compartment located under the rear floor.

Storage Capacity

Engineers configured MDX to handle a wide range of contemporary family storage needs. In addition to the center console bin and beverage container holders, MDX has a long list of built-in features that can be easily adjusted as necessary to serve drivers of premium SUVs.

The hinged glove box is illuminated, lined with flocking material, and lockable. A motion damper allows a controlled, fluid opening motion - preventing the lid from banging open against a front passenger's knees.

The front door pockets are purposely configured to hold maps, guide books, and road atlases while the rear door pockets are just right for sunglasses, small toys, treats, and bottled beverage containers. Armrests for the third-row seating area have small storage boxes covered by latchable lids. A rear under-floor compartment is ideally located for easy access through the open liftgate. Pockets stretched across the rear of the front bucket seats are ideal for storing a variety of things for easy access by front-row and second-row passengers.

MDX's impressive cargo volume - the single attribute that attracts most buyers to SUVs in the first place - is, as you would expect, versatile and practical. Four-foot wide sheets of building materials slide in between wheel wells with ease - an attribute not matched by MDX's direct competitors. With second- and third-row seats folded down, MDX offers 82 cubic feet of cargo space, enough to accommodate virtually whatever you may need to carry.

A low load floor and seats that fold flat are the keys to versatility. To simplify conversion of the seats to a cargo area, the third-row and second-row center seat belts easily detach from their floor anchors with a patented and simple-to-use mechanism. Six cargo tie downs are located
strategically around the perimeter of the load floor to help secure objects susceptible to sliding or rolling. And since both the second- and third-row seats are split designs, six cargo/seating configurations are possible to suit carrying needs. Various accessory hardware is available from Acura dealers to safely and conveniently carry bicycles and other gear inside the vehicle and the roof rack (optional on MDX ,standard with Touring Package) is useful for hauling skis, surfboards, or bulky camping equipment.

Thanks to the wide-opening liftgate and flat floor, large items, such as the box for a 32-inch TV will slide right into place for convenient transport. And it is possible to tote home 15, 3-cubic-foot bags of garden mulch without blocking outward vision. When the middle seating row is in use, there's still 22-cubic feet of space available, more than a full size car's trunk. And if it is necessary to use all three rows of seats, MDX still provides 7.6-cubic feet of space behind the third-row seat - enough for eight paper grocery bags, four duffels and a cooler, or a full set of golf clubs.

A separation net is offered as a dealer-installed accessory that attaches to four built-in attachment points, two in the floor and two in the ceiling, and provides a separate area for cargo behind the second row of seats, along with a cargo liner and liftgate apron that can be folded out over the rear bumper when the liftgate is opened.

Synchronized Climate Control System

After analyzing competitive SUVs, it was clear to MDX engineers that significant strides could be achieved by offering climate control comparable to a luxury sedan instead of merely matching existing truck comfort standards. The resulting climate control system became a primary attribute of the MDX.

The patented dual Synchronized Climate Control systems are normally linked in operation to improve heating and cooling performance by a full five minutes (17 percent) over use of the front system alone. The result is that comfortable conditions are achieved in every seating position in the shortest possible time after start up in hot or cold weather.

The ventilation control panel is positioned centrally on the instrument panel above the trip computer and navigation system display screen. It consists of eight buttons that operate the front and rear heating and cooling units. One button controls full automatic operation in conjunction with up and down temperature-select buttons and a set-temperature display window. Alternatively, the "Rear A/C Manual" button can be pressed to give the second-row passengers control of the ventilation system in their area. Rear controls include a temperature-set knob, upper or lower air flow select buttons, and another knob to adjust fan speed.

Cooling and heating equipment for the rear seat is neatly packaged in the lower part of the center console. There's a blower capable of moving up to 392-cubic yards of temperature-controlled air per hour, a 2500-watt air-conditioning evaporator, and a 2800-watt water heater core. Concealed ductwork provides heated air to both second and third row passengers, and cool air to second-row occupants.

Total capacity of the linked front and rear systems is 19,000 BTUs which slightly exceeds the heating and cooling capacity found in the average American home. Unlike some rear-, or roof-mounted climate control systems, MDX's equipment doesn't intrude on cargo or head room or interfere with the moonroof.

Flexible Center Console Design

As a focal point of the interior design, MDX's center console is an extraordinarily versatile design. It is neatly integrated with the instrument panel design, it houses heating and air conditioning equipment for the benefit of rear-passenger comfort, and it provides a long list of storage and convenience features.

Additional details include a storage area for small objects ahead of the shift lever area occupied by the DVD player in models equipped with the Rear Entertainment System, two covered cup holders for front passenger use, and a climate-control vent and switch panel on the rear-most surface. For a luxury appearance, lower side surfaces are carpeted and wood-patterned panels trim the forward horizontal surfaces. A mat in the bottom of the forward bin is removable for cleaning.

The main storage compartment lid is padded to provide a comfortable armrest surface. This lid opens either to a 95-degree position for access to the interior compartment or to a 180-degree position to act as a second-row serving tray. Two cupholders and a wide depression to hold snacks are molded into the lid's inner surface.

Inside the storage compartment, a hinged top tray offers a convenient storage location for tissues, writing materials, or a cellular telephone. An access hole located in the rear corner of this tray provides a path for the phone's power cord to plug into a 12-volt power outlet below. Clearance is also provided to permit closing the top tray while the phone is in use. Below the top tray is a second large-volume storage compartment. A mid-level shelf, lined with soft materials to prevent damage to small objects, is an ideal location for credit card or magnetic access (key) card storage. The remaining volume is large enough to accommodate either a home-size tissue box or up to 13 compact discs inside their jewel cases.

Instrument Panel Layout

As in other Acura vehicles, the driver's cockpit is organized ergonomically to avoid distractions from the task of driving. Exterior lighting and turn signals and cruise control are positioned to the left of the steering wheel to prevent operation by passengers, while wiper controls are mounted on a right-side column stalk. Radio and cruise control switches are positioned just below the horizontal steering wheel spokes for easy use. Secondary switches are spotted near the instrument cluster. Moonroof controls are incorporated into the roof console.

A three-dial instrument cluster conveys vehicle system information to the driver: engine rpm, vehicle speed, fuel level, coolant temperature, and shift-lever position. The instrument cluster features meters backlit with ambient blue lighting, making them easy to read and providing an attractive, modern appearance. An array of indicator lights is positioned at the bottom of the tachometer and at the top and bottom of the combination temperature gauge and fuel level display. The speedometer is marked in both mph and kph to a full scale reading of 140 mph/225 kph.

Center Display Screen

The centerpiece of the instrument panel is a large multi-function display screen. MDX models not equipped with the Acura Navigation System feature trip computer, compass, and climate control information in this highly visible location. The seven-inch (diagonal measurement) LCD screen is flat with a curved bezel. It displays current and average fuel economy, range remaining, compass heading, outside temperature, time of day, climate control mode, air-conditioning on/off, and fan speed. A trip button to the left of the display cycles between trip and mileage information. A separate button resets fuel economy, trip mileage, and elapsed time registers. There's also a slide switch to adjust the brightness of the display screen.

Pressing an on-screen mode button varies the direction of air flow through the front climate-control system. Pressing an A/C button switches the A/C compressor on and off. The fan button selects from five speeds.

Adjacent to the central display screen are two adjustable vent registers, a master light switch, a hazard switch, a "passenger airbag off" indicator and a small control panel for managing the synchronized front and rear climate control systems.

HandsFreeLink™ Wireless Telephone Interface

The MDX equipped with the Touring Package features a standard HandsFreeLink™ hands free phone interface that is designed to work with many recently manufactured Bluetooth-enabled mobile phones (sold separately). Bluetooth is a radio frequency-based cable replacement technology that lets portable devices like mobile phones PDAs, laptops and other devices communicate wirelessly. The HandsFreeLink system is compatible with Bluetooth enabled cell phones that have the Hands Free Profile (HFP). Some early Bluetooth-enabled phones do not have this communications protocol, but any newly released phones should have the HFP. After the driver completes a one-time "pairing" process, the MDX can communicate wirelessly and securely with the driver's cell phone when it's within about 10 feet of the car. The phone needs to be on, but can be stowed in a pocket, briefcase or purse-or anywhere inside the MDX cabin.

HandsFreeLink allows the driver to send or answer calls without taking his or her hands from the steering wheel. When a call comes in, the number of the incoming caller is displayed on the Multi-information display located in the speedometer face. The phone ring tone is also played over the audio system. If the driver chooses to answer the call, a press of the steering wheel-mounted "Pick up" button mutes the audio system and the incoming caller is heard over the audio system speakers. An overhead microphone picks up the driver's voice. Algorithms built into the HandsFreeLink™ system cancel "echo effect" and reduce background noise to improve the transmission quality of the driver's speech.

To send a call hands free, the driver can dial the number by voice, again using fingertip controls mounted on the steering wheel to activate the system. The driver also can store frequently called numbers with voice tags in the system's memory. Up to six different compatible mobile phones can be paired with the HandsFreeLink™ system at one time.

Acura Navigation System With Voice Recognition

The MDX features the DVD-based, satellite-linked Acura Navigation System with Voice Recognition as an option on the model with Touring Package. The system includes enhanced voice recognition ability and the ZAGAT Survey Restaurant Guide. Some of the system's features include:

• Fast system start-up time, route calculation and search speed
• Over 560 navigation voice commands minimizes the need for manual character entry
• Voice recognition system recognizes city and street names as spoken words, a comprehensive destination guide with seven million points of interest are stored on an updateable DVD
• Business and recreation directory of virtually the entire continental United States and Hawaii complete with phone numbers
• Rearview camera
• 3-D graphics for freeway on and off ramps
• 8-inch touch screen display
• Split screen mode for displaying additional route information
• Day/night visualization modes with user-selectable screen background appearance
• Turn by turn voice guidance in either male or female voice
• Zagat Survey Restaurant Guide
• Make calls to on-screen points of interest with HandsFreeLink
• User selectable Day/Night screen or display off modes
• Trip routing can include up to five user-chosen way points
• Trip routing can avoid user-selected areas
• Exit list shows what businesses are available at a given highway exit
• On-screen picture of highway interchanges indicates which lane to use to stay on route
• Larger on-screen fonts and buttons for better visibility
• Greater map contrast and simplified visual presentation

System Operation

Based on positioning data from up to 12 orbiting Global Positioning Satellites (GPS), the Acura Navigation System with Voice Recognition tracks the vehicle's position. If the GPS antenna is blocked by a tunnel, tall building or parking garage, an internal gyroscopic system and a speed sensor track the location of the vehicle to keep the mapping information current and reliable until satellite reception is restored. A DVD is located in the trunk in the system's ECU. Updated DVD data discs are available on an annual basis on-line or by calling a toll-free number.

The system can be controlled by voice, or by choosing menu options or spelling out a word through a touch-sensitive on-screen keypad. Only a few entries are needed to enter destinations and route calculations are made expeditiously.

A matte finish is used on the display screen to enhance legibility while resisting fingerprints. The same screen used for navigation also displays trip distance, average fuel mileage, remaining range (miles to empty), elapsed time, outside temperature, and climate control setting information.

For voice operation, the driver simply presses the "Talk" button on the steering wheel and says any of a number of preset command phrases. The system responds to over 560 command phrases, as well as to spoken city and street names.

When the "Talk" button is pressed, the audio system is automatically muted, and an overhead microphone receives the command from the driver. Commands can be given in plain English, like "Display gas stations, "Find nearest hospital" or "Find nearest Chinese restaurant." You can choose to display points of interest on the map (like restaurants, or grocery stores, for example), or have the system provide turn-by-turn navigation- all by voice. The extensive point-of-interest database includes phone numbers, which can be dialed easily by using the HandsFreeLink™ system and the driver's cell phone.

Compared to the previous generation Acura navigation system, the MDX system start-up time has been reduced and search speed increased significantly.

If desired, a route with up to five destinations can be pre-programmed. The Acura Navigation System with Voice Recognition has the ability to track vehicle position by means of dots on the screen for those areas not covered by DVD map data - especially helpful when driving off-road.

The onboard database includes the Zagat Survey Restaurant Guide and a highly accurate all road database. The expansive voice control system saves time and simplifies operation of the system. Sophisticated voice recognition technology allows the MDX owner to simply speak city and street names aloud, and the system responds by displaying matches available in the database.

Another notable element is the addition of a rearview camera. This camera, located on the liftgate sends a picture of the area directly behind the MDX to the navigation system screen when the transmission is moved to the "reverse" position. The view shown extends to over 13 feet behind the bumper with a view width that is wider than the MDX itself.

Highly Engineered Cup Holders

MDX engineers conducted a major cupholder R&D program to make the MDX extremely occupant-friendly. The first thing they learned was the daunting array of beverage containers in daily use - rectangular juice boxes, 12-ounce cans, 20-ounce bottles, various-sized paper cups from fast-food outlets, insulated coffee cups, and bottled water vessels galore. Ten beverage holders were designed into the MDX's interior to accommodate a variety of passenger needs. Real innovation was necessary to accommodate as many different sizes and types of containers as possible and to securely hold them during stopping and cornering maneuvers. For example, pockets built into the bottom portion of the rear door trim are purposely deep to hold either a 20-ounce soda bottle or larger bottled water containers. Cup holders molded into the armrest areas adjacent to the third-row seat feature notches necessary to accommodate juice boxes. Cup holders positioned near the center of the vehicle (two ahead of the storage console, two built into the console lid's inside surface, and two more integrated with the fold-down, second-row armrest) have stepped bottom surfaces to grab and hold different-diameter containers. Front-seat cup holders are a three-tier design with a rubber lip to help restrain a teetering container. Third row cup holders are also a three-tier design, but without a rubber lip, while second-seat cup holders are a slightly shallower, two-tier design.

Standard Music System

MDX sound systems are engineered for optimum performance and tuned specifically for this vehicle's acoustical characteristics. The standard system provides premium sound quality and clarity, especially in the first and second seating rows. A head unit integrated into the center-dash features AM/FM stereo, cassette, XM® Satellite Radio and 6-disc CD changer. A micro antenna positioned at a discreet center-rear location on the roof receives radio broadcasts. Switches mounted below a left-side steering wheel spoke allow the driver to adjust play volume, choose another radio station, or select a different CD track without shifting attention from the road.

This system features standard XM® Satellite Radio. XM® Satellite Radio provides more than 100 channels (all 68 music channels are commercial-free) of digital program material with near-CD quality sound. A text display provides information text on the program material. XM® provides virtually uninterrupted coverage of the 48 contiguous states, and a three-month subscription is included with the MDX. Note that XM® Satellite Radio is not installed on MDX models sold in Alaska and Hawaii- service for these states does not exist at this time.

Four integrated, 30-watt amplifiers and one 35-watt amplifier drive a total of seven speakers. A 16 cm midrange speaker is mounted in each door. There's also a 2-inch tweeter in each front door and a 10-inch sub-woofer in the right-rear interior trim panel.

Acura/Bose ® Music System

The MDX with Touring Package is equipped with an Acura/Bose® Music System that features a powerful 225 watt amplifier, high power neodymium magnets in the front and rear doors and high power rear twiddlers working together to provide superb entertainment in all seating positions.

The head unit is curved in two directions to coordinate with the center-dash design. This system offers AM/FM, cassette, a 6-CD in-dash changer and standard XM® Satellite Radio. The steering wheel-mounted controls described above also command the system.

A six-CD changer function allows the unit to conveniently store extra discs ready for playing without a separate magazine. Touching a load button once opens the changer's door to allow the insertion of one CD. Holding that button down facilitates loading up to six CDs. Since the door opens only during loading and eject operations, there's less likelihood that foreign objects will jam the mechanism. This sound system can select any desired CD track or shuffle through stored material at random to provide hours of audio entertainment.

The Acura/Bose Music System features eight speakers including a powerful rear-mounted 2.5-inch twiddler speaker. Six integrated 37.5-watt amplifiers drive the mid-range, tweeter, and twiddler units, and a 10-inch sub-woofer.

Rear Entertainment System

The MDX can be equipped with an available factory-installed Acura Rear Entertainment System. This multi-faceted system features a 7-inch wide screen LCD display (for optimum visibility) that flips down from the ceiling at the push of a button for easy viewing by rear seat passengers. The extended capabilities of the DVD system allow for either DVD, CD, radio, cassette tapes and auxiliary accessories (such as video games, VCRs or cameras) to be played in the rear seating areas while the front passengers listen to a different audio source.

The DVD player can be conveniently controlled from three locations - the front audio system controls, the rear seat controls near the LCD screen, or a wireless remote control. Additional
audio and video input jacks allow for a wide variety of additional equipment - ranging from camcorders to VCRs to game consoles - to be attached to the system. The system comes with two infrared (IR) wireless headphones and a wireless remote control as standard equipment.

Onstar® In-Vehicle Communications and Assistance Service

All MDX models equipped with the Acura Navigation System with Voice Recognition are also equipped with standard OnStar service in-vehicle communications and assistance service. OnStar can offer emergency assistance, accident notification, air bag deployment notification, stolen vehicle tracking, door unlock command and vehicle tracking, plus other features that provide an extra level of security and convenience.

Pressing an activation button located in the overhead console provides quick access to a live OnStar service advisor 24 hours a day. Using input from orbiting GPS satellites, the OnStar service advisor can easily pinpoint the location of the owner's vehicle to help provide assistance.

In the event of vehicle theft, subscribers need only contact the OnStar Center (after filing a police report) and provide a personal identification number. An OnStar service advisor can then pinpoint the car and direct authorities to its location.

The OnStar service system is integrated into the car's suite of electronic conveniences. This allows the system to dial phone numbers displayed on the navigation system by automatic voice command.

This version of OnStar service is equipped with a Digital/Analog Tri-mode phone. This means that in addition to Analog communication, the phone operates on both CDMA bands (Cellular and PCS) used by all CDMA digital networks in the US.

OnStar Personal Calling offers a hands-free, voice-activated, wireless phone that is built into the system in case the driver's hand-held cell phone is lost, forgotten or has a low battery. Personal Calling can be activated at the same time the OnStar service account is activated online, or by pressing the blue OnStar service button at anytime and talking to the Advisor. Pre-purchased minutes can be billed to a credit card. There is no activation fee or additional long distance or roaming charges.

In the MDX, phone numbers can be dialed through OnStar Personal Calling. Customers can speak the phone digits they wish to dial in a steady stream, with no pauses (e.g., "2485551212"), rather than pausing between digits.

The MDX comes with a free three-month subscription to the Safe and Sound Plan. In addition, MDX owners can choose to upgrade to the Directions and Connections Plan ($399 per year) which adds route support, convenience services and ride assist.

Finally, a Personal Calling Package, which includes wireless phone and "Virtual Advisor" Internet services, is available as part of both plans for an additional charge.

Interior Illumination

Overhead lamps are provided for all three rows of seating. An additional cargo light mounted to the tailgate provides ample illumination both inside the vehicle and on the ground for convenient loading at night and lights in the footwells of the front seats allow for easier entry and egress at night. When the lamps are switched off by closing the doors or inserting a key in the ignition switch, they fade out over a six-second period.

Ambient illumination is also provided for front seat occupants. A subtle pale blue light is emitted from the footwells and shifter column during night driving providing occupants with a warmer cabin feel and giving off just enough light to help improve occupant's visibility within the vehicle. The ambient lighting is extinguished when the headlights are turned off. All power window switches are illuminated for convenient night-time operation.

Keyless Security System

To avoid interference from cellular telephone and pager transmissions, MDX's keyless security system communicates via FM (instead of AM) signals. In models with the Touring Package, when doors are unlocked remotely, outside mirrors and the driver's seat automatically move to
pre-selected memory positions. Two fobs are provided to distinguish one driver in the family from another.

The fob itself has three buttons. At the top, there's a large triangular-shaped button to command the lock function. A smaller round button with a raised nib for tactile identification commands the vehicle to unlock all doors. Operation of the locks is confirmed by an audible chirp. The third button at the bottom of the fob is recessed; pressing this "panic" button activates loud dual trumpet horns to signal distress.

2006 Acura MDX - Safety

Introduction

The Acura MDX SUV is engineered to meet and often exceed all applicable safety standards. Safety, security, and accident avoidance are main Acura priorities. With that in mind, various systems - body structure, chassis, driveline, passenger restraints - interact positively to help the driver steer clear of hazards whenever possible and enhance occupant protection in the event an accident is unavoidable.

The Variable Torque Management (VTM-4) all-wheel-drive system is the key to sure-footed handling and straightforward controllability whether the pavement is dry or wet and slippery. Combined with MDX's Vehicle Stability Assist (VSA), 4-wheel independent suspension, torque sensing power rack-and-pinion steering, and four-wheel-disc brakes with ABS, VTM-4 delivers best-in-class traction to enhance the driver's ability to guide an MDX safely out of harm's way.

To help safeguard occupants from injury when a collision is unavoidable, MDX provides multiple layers of protection. The computer-engineered body structure features front, side and rear crumple zones to help protect occupants during offset and side impacts, and a well protected fuel tank. Extensive use of high-strength steel yields a robust safety cage surrounding passengers without incurring an awkwardly heavy curb weight.

All seating positions have three-point seat belts. Front seat belts are equipped with pretensioners and automatic load limiters that are activated in certain collision conditions. The MDX comes with standard front dual stage, dual threshold front airbags. These airbags can deploy at the most appropriate of two rates depending on the severity of the crash. In addition, if the driver's or passenger's seat belt is not fastened, the air bag deploys at a lower collision speed to help offer more protection to the unbelted occupant. Additionally, the MDX features two weight sensors in the front passenger's seat and a driver's seat position sensor as part of the dual-stage, dual-threshold front airbag system.

The driver's and front passenger's seats also feature side airbags mounted in the seat bolster closest to the door. The passenger's seat is equipped with a system of sensors designed to disable side air bag deployment and prevent injury to a small child (or small-statured adult) if they lean into the side air bag deployment path. Once the child returns to an upright seating position, the side air bag will reactivate so it can deploy and protect the child in a side impact.

Helping protect all three rows of occupants in all MDX models is the roof-mounted Side Curtain Airbag system with side impact and rollover sensors. In addition to the side impact protection, this system can activate in the unlikely event of a rollover. Depending on the speed of the vehicle and the rate of roll detected by the sensors, side curtain airbag deployment timing is varied to best protect outboard occupants in the event of a rollover - faster for a sharp roll rate such as encountering a steep embankment, slower in the case of losing balance after hitting a curb or like structure.

From front passenger, side passenger and side impact crash tests conducted by the National Highway Traffic Safety Administration (NHTSA), the MDX achieved the highest possible rating of "five stars" in all three crash tests.

Safety Structure

MDX engineers used powerful computers to assure that this vehicle's safety cage structural design would perform well even before physical prototypes were built. Crash simulations helped reveal areas of the design that needed more - and sometimes less - reinforcement to absorb energy while resisting intrusion.

MDX has an especially robust floor construction to optimize both rigidity and resiliency. Two longitudinal rails run continuously from bumper to bumper. The rails are buttressed by a total of eight box-section crossmembers and two bumper bulkheads. This provides the strength needed to resist standard barrier impacts at the front and rear, offset crashes (wherein most of the load is applied longitudinally to one corner of the vehicle), and side impacts.

A four-ring shell-type safety cage is used to help protect occupants with A, B, C, and D pillars that run continuously to avoid intrusion during side impacts. To meet current federal head-impact requirements, roof-pillar trim and headliner materials absorb energy and help reduce the likelihood of occupant head injury. Stiffeners inside the doors at the beltline provide a continuous horizontal connection between the first three pillars. Tubular beams are welded inside the doors at wheel height to provide additional intrusion resistance.

One quarter of the body structure - longitudinal rails, floor crossmembers, pillar reinforcements, and bumper beams - is made of high-tensile steel for maximum strength with minimal weight.

MDX's fuel tank is made of highly puncture-resistant, six-layer, high-density molded-polyethylene, with high-strength, box-section floor reinforcements to help guard it from side collision damage. It is located ahead of the rear axle for protection.

Frontal Restraint Systems

Unlike some SUVs, MDX provides a three-point restraint system for all seven seating positions. A special roof-mounted reinforcement, positioned between the C and D pillars, serves as a rigid mounting point for the second row, middle passenger's shoulder belt.

Front seat belts are equipped with pretensioners and automatic load limiters that are activated in conjunction with the front airbags.

Dual-Stage, Dual Threshold Front Airbags

The MDX is equipped with dual-stage, dual-threshold airbags for the driver and front passenger. These airbags are designed to minimize the potential for airbag injury while providing head and chest protection for the occupants in the event of a collision. This front airbag system features additional sensors; front passenger seat weight sensors, and a driver seat position sensor designed to enhance occupant protection.

The MDX's front airbags can deploy at one of two rates. Deployment of the driver's side airbag takes into account the severity of the crash, whether or not the driver's seat belt is fastened and the position of the driver's seat. During a lower speed collision, the airbag inflators are triggered in sequence, resulting in slower overall airbag deployment with less initial force. The same sequence is also utilized regardless of collision speed if the driver's seat is within a half inch of the full forward position. During a higher speed collision, if the driver's seat is more than a half inch from the full frontal position, both inflators operate simultaneously for full, immediate inflation. Airbag deployment on the front passenger's side is regulated by crash severity, seatbelt usage as well as the weight of the occupant. Sensors under the seat gauge occupant weight and if the total weight on the passenger seat is less than 65 lbs, the airbag system will not deploy, minimizing the potential for injury to children. Just as the driver's side, the airbags are deployed at the speed appropriate to the speed and severity of the collision - slower for lower speed collisions, more quickly for higher speeds.

The driver's airbag is located in the steering wheel hub and the passenger's airbag is located on top of the dash. As in all Acura vehicles, the front passenger's airbag is designed to deploy upward toward the windshield and then back toward the occupant. This provides a large cushion to help protect the front passenger.

Side Airbag System

Like other Acura models, MDX is equipped with seat-mounted side airbags to help safeguard the driver and front passenger from side-impact injury. An innovative occupant position detection system is used to assure that the passenger's side airbag has a clear path for deployment. In the event a child (or a small-statured adult) leans into the deployment path of the side airbag, a seven-segment antenna system built within the backrest signals this condition to an electronic control unit (ECU) also located within the seat. The ECU then deactivates the side air bag from functioning and triggers a "SIDE AIRBAG OFF" indicator light in the instrument cluster. After the front occupant returns to a normal seating position, the side air bag module automatically resumes full-functional status.

Side Curtain Airbag System

All three rows of occupants are protected by Acura's roof-mounted Side Curtain Airbag System, which is standard equipment on all MDX models. The side curtain airbags deploy from a module in the roof in the event of a sufficient side impact, providing an important and significant level of head protection in the window area. In the unlikely event of a rollover, a roll angle sensor along with lateral G and transverse G sensors, located just in front of the windshield base determine the rate of roll and deploy the side curtain airbags accordingly.

Like the other airbag systems in the MDX, the side curtain system utilizes sensors to determine the most appropriate deployment timing of the airbags in the event of a rollover.

The system uses algorithms to continually evaluate the situation and determines whether a rollover is eminent. The system responds to the three types of rollover "scenarios" drivers would potentially encounter: the "curb trip rollover" which as its name suggests, results when one side of the vehicle hits a curb or like object; the "soil trip rollover" which can result when one side of the vehicles suddenly comes into contact with a different surface type, often involving a slight elevation change; and finally, the "screw rollover." This type of rollover is usually the steepest and fastest of the rollovers whereby the vehicle comes upon a sharp angle such as an embankment. The gyro roll and lateral G-roll sensors determine the "scenario" and calculate the rate of roll and the speed of the vehicle in order to deploy the airbags at the correct stage for optimum protection. Similar to the dual-stage, dual-threshold front airbags, the side curtain airbags will deploy at the faster or "full" rate in the case of a screw rollover and more slowly in a curb trip rollover. In the case of a rollover, the side curtain airbags on both sides of the vehicle will deploy. However, in the event of a sufficient side impact that does not result in a rollover, only the airbags on the impacted side of the vehicle will deploy.

Tire Pressure Monitoring System

The MDX is equipped with a direct Tire Pressure Monitoring System (TPMS). Using a series of four sensors and four initiators (one for each tire) and a receiver to capture and relay information, the system alerts the driver when it detects that tire pressure in one or more tires drops significantly below the recommended pressure.

The sensor transmitter is located inside the wheel. Should the tires be rotated around the vehicle due to normal maintenance or be replaced entirely, the new tires are "auto-located" by the system. If the system detects that tire pressure is significantly low (32 psi is recommended), the low tire pressure indicator located in the meter containing the fuel level and temperature gauge will come on while a schematic of the vehicle located in the center meter housing the speedometer will indicate which tire or tires is low.

Anti-Theft Alarm System

MDX has a standard keyless-remote entry system that locks and unlocks all doors and the rear hatch at the push of a button. To enhance theft protection, only one key lock mechanism is provided for the driver's door position. The same key fob used to lock the doors also activates the MDX's security system. In response to any attempt to enter the vehicle without the key fob or ignition key, the horn sounds, and the flasher lamps are activated. If need be, the alarm system can be triggered to summon help by depressing a "panic" button on the remote-keyless fob.

Security/Immobilizer System

Imbedded within MDX's ignition key is an electronic microprocessor circuit that communicates with a receiver in the ignition switch to enable the vehicle's electrical systems. Forcibly vandalizing the ignition switch, hot-wiring, or attempting to start the car with a key lacking the microprocessor circuit will result in immobilization. Without proper key-to-immobilizer communication, the MDX will simply not start.

Lower Anchors and Tethers for Children (LATCH) System

The Lower Anchors and Tethers for Children (LATCH) system is standard on the second row of outboard seats. The LATCH system features built-in, ready-to-use anchors and tethers allowing compatible child safety seats to be installed without using the vehicle's seat belt system.

2006 Acura MDX - Quality & Manufacturing

Introduction

Like all Acura products, the MDX benefits from an integrated approach to designing manufacturing quality into the original plan for the vehicle. This approach results in a vehicle that is sure to achieve the legendary durability, quality and reliability that is the hallmark of all Acura vehicles. To achieve the specified targets for quality, the MDX team had to carefully consider the logical assembly of components as well as the effects of time and wear on each part and system.

The development team conducted testing on three continents and covered thousands of miles of testing varying from bitter cold to sweltering heat, adding in variables of high and low altitude environments, with full loads and a battery of tests that left nothing to chance. These tests confirmed that MDX will perform at its impressive levels for years to come.

The following are a few of the many areas that show the attention to detail that typifies the design and engineering behind the MDX.

Minimizing Noise, Vibration, Harshness

A quiet interior is essential to any high quality vehicle. Towards that end, MDX engineers incorporated a host of design features and refinements aimed at blocking NVH from the passenger cabin. These include:

• Acoustic windshield glass
• Thinsulate added to the sideview mirrors
• Magnetic melt sheets

All powertrain-related hardware is double isolated from the main body structure by use of rubber mounting systems. A perimeter-type front subframe supports the engine, transaxle, steering, and front suspension lower control arms. Two engine mounts are hydraulic designs with internal damping, one of which is Electric Control Mounting (ECM) to provide excellent isolation throughout the broad range of excitation frequencies. An assortment of tuned-mass dampers attached to both the engine mounts and the subframe counteract resonance. A dual-path upper mount is used between each front spring and strut unit and the body structure.

The front axle half-shaft inner joints are designed with internal rollers that minimize friction. A two-piece tubular propeller shaft is used to transfer torque with no susceptibility to whip or vibration. A dynamic damper positioned inside the front tube is tuned to cancel out vibration at cylinder-firing frequencies. The rear drive unit is supported by three rubber mounts in a second subframe, which is in turn attached to the body structure through four widely spaced rubber mounts. Rear coil springs are insulated from both the body and the rear suspension hardware by means of upper and lower rubber pads.

Various fuel tank subsystems - the fuel vapor canister, the assembly, and the ABS modulator - are rubber isolated from the body to block any sympathetic NVH contribution.

The engine's high volume intake and exhaust systems are engineered for non-restrictive but quiet flow through the engine. Just aft of the point where left- and right-bank exhaust flow join, a corrugated flex pipe is positioned to permit quiet movement between the engine and the remainder of the exhaust system. A large pre-chamber muffler near the middle of the vehicle is glass-filled to absorb high-frequency exhaust noise. The high-volume silencer near the rear bumper has dual outlets to ensure exhaust flow requirements are met during full throttle acceleration.

Extensive sound deadening is used within MDX's body structure. Magnetic melt sheets improve isolation from road noise and reduce overall weight of the vehicle. The melt sheets - whose particles bond to surfaces in the paint ovens - cover virtually the entire floor of the vehicle from the vertical dash panel to the liftgate sill. An acoustic roof lining runs from front to rear while additional sound-deadening material blankets the dash panel and the rear of the hood. Molded rear fender liners help quiet road splash and tire noise. Acoustic windshield glass reduces cabin noise. To create a noise barrier at the base of the A, B, and C pillars, expanded foam fills these cavities. This foam is expanded by the heat of the paint-curing ovens, noise from the floor area is blocked from being transmitted inside the pillar cavities to the interior compartment.

Special recycled textile absorption blankets are attached to the underside of the instrument panel and the sides of the center console.

Design of the door mirrors is especially sensitive to wind noise. The MDX features diffuser side mirrors that smoothly channel air between the mirrors and the window glass for reduced wind noise. A layer of Thinsulate® has been added to the side mirrors to further reduce wind noise. Sponge material between the base and the door surface eliminates the possibility of gaps in that area. The molding to base interface is also a zero-gap design.

Additional weatherstrips are positioned in critical window frame to pillar gaps to help maintain smooth air flow down the side of the vehicle.

The bottom line is a net lack of road, powertrain, and wind noise inside the passenger compartment. In competitive tests, MDX compares favorably with the best luxury-class SUVs in overall NVH performance.

Quality Craftmanship, Quiet Interior

The MDX is the first sport utility vehicle designed with a no compromise engineering philosophy. MDX delivers fresh styling, unmatched versatility, car-like driving exhilaration, class-leading safety and environmental responsibility while also upholding Acura's well established reputation for outstanding value. Acura customers expect best in class quality. Towards this end, MDX has the refined attention to detail lacking in several of its luxury SUV class competitors.

Body gaps are best in class by an impressive margin. Exterior design is clean, functional, and well proportioned. Adornments are elegant and tasteful. Door jams are neatly finished. MDX sets a new standard for quality craftsmanship in its class.

Door Handles

MDX's pull-type door handles are chrome plated for a luxury look and feel. Clearance pockets behind each release handle are generously sized to provide room for gloved hands and to avoid ring and fingernail scratches.

Tight, Consistent Panel Gaps

To minimize construction tolerances, MDX's doors are attached to the car by rigid bolts that pass through zero-clearance hinge holes. Doors are made of high-strength, galvanized steel for dent resistance. Front mud guards are provided to deflect rocks and debris and rear splash guards are standard accessories. Lower door surfaces are painted with a soft primer that is especially resistant to stone chips. Seals that extend from the lower edges of the doors to the sill area block the build up of dirt and debris that might otherwise soil clothes during entry and exit from the vehicle.

Most MDX gaps are between 0.12- and 0.18-inch. To permit a tighter fit between rear quarter window and the adjacent quarter panel, a beveled edge is used on the glass.

Seals and covers are positioned in door jams and sill areas to mask assembly welds. In the liftgate opening, the trim has a clean appearance that's not marred by the visible bumper clips used by some competitors. All interior trim is retained with hidden fasteners. Front and rear wipers are smooth, single-piece designs for a clean look.

Door mirrors have blue-tinted glass to cut glare at night. Electrical heating grids can be activated by a switch near the remote mirror control pad to clear frost and fog from the mirror surface.

Side and rear window glass is deeply tinted for privacy and to keep the interior cooler during summer months.

Manufacturing

The MDX is built at Honda of Canada Manufacturing in Alliston, Ontario, near Toronto.