OVERVIEW
The TL is powered by an aluminum-alloy 3.2-liter V-6 that uses advanced Acura technology to provide an exceptionally high level of power and refinement. The new VTEC V-6 generates 270 horsepower and 238 lbs-ft of torque-far outpacing the previous generation 3.2 TL (225 horsepower and 216 lbs-ft), and even the 3.2 TL Type-S (260 horsepower and 232 lbs-ft). Compared to the previous generation TL and TL Type-S, the new TL engine delivers identical EPA estimated city and highway mileage* when paired with the Sequential SportShift automatic transmission. In terms of emissions performance, however, it meets CARB LEV-2 ULEV requirements, a much tougher standard than either of its predecessors.
For the first time ever, the TL offers an available 6-speed manual transmission at no extra cost. With short shift throws, closely spaced ratios and slightly shorter (higher numerically) overall gearing, the 6-speed manual transmission is targeted at drivers interested in extracting the maximum performance-and hands-on fun-out of the most powerful V-6 engine in the class. A helical gear-type limited-slip differential is applied as standard equipment in the 6-speed manual transaxle, providing maximum grip and handling stability under heavy acceleration.
Engine Comparison
2004 Acura TL |
2004 Acura TL |
2003 Acura 3.2 TL |
2003 Acura 3.2 TL Type-S |
2003 BMW 530i |
2003 Infiniti G35 |
2003 Lexus ES 300 |
2003 Mercedes-Benz C320 |
|
Engine |
3.2-liter SOHC VTEC V-6 |
3.2-liter SOHC VTEC V-6 |
3.2-liter SOHC VTEC V-6 |
3.2-liter SOHC VTEC V-6 |
3.0-liter DOHC I-6 |
3.5-liter DOHC V-6 |
3.0-liter DOHC V-6 |
3.2-liter SOHC V-6 |
Horsepower @ rpm |
270 @ 6200 |
270 @ 6200 |
225 @ 5600 |
260 @ 6100 |
225 @ 5900 |
260 @ 6000 |
210 @ 5800 |
215 @ 5700 |
Torque @ rpm (lbs-ft) |
238 @ 5000 |
238 @ 5000 |
216 @ 4700 |
232 @ 3500-5500 |
214 @ 3500 |
260 @ 4800 |
220 @ 4400 |
221 @ 3000 |
Standard transmission |
5 AT |
6MT |
5 AT |
5 AT |
5 MT |
5 AT |
5 AT |
6 MT |
EPA estimated mileage City/Highway |
20/28 |
20/30 |
19/29 |
19/29 |
21/30 |
19/26 |
21/29 |
17/25 |
POWERTRAIN AT A GLANCE
Engine
- 3.2-liter, SOHC, VTEC V-6 engine produces 270 horsepower at 6200 rpm and 238 lbs-ft of torque at 5000 rpm
- Increased torque from the previous TL-S from 3500 rpm to redline
- Intake-side three-rocker VTEC (Variable Valve Timing and Lift Electronic Control)
- 11.0:1 Compression ratio
- High flow cold air induction system
- High flow exhaust system with closed coupled and under floor catalytic converters
- 2-stage tuned intake manifold
- Drive-by-Wire Throttle System™
- Computer-controlled Programmed Fuel Injection (PGM-FI)
- Direct ignition system
- Serpentine accessory belt
- Maintenance Minder system which optimizes service intervals
- 105,000-mile tune-up interval
Emissions/Fuel Economy
- Compact in-head exhaust manifolds
- High flow close-coupled catalytic converters plus under floor catalytic converter
- High capacity 32-bit RISC processor engine control unit
- Meets CARB LEV-II ULEV standard, which cuts NOx by 75% compared to LEV-I LEV
- Estimated mileage of 20/28 mpg (City/Highway, 5 AT) and 20/30 mpg (City/Highway, 6 MT)
6-Speed Manual Transmission
- Close ratio spacing for maximum performance
- Lightweight high-pressure-cast aluminum-alloy transmission housing
- Multi-cone synchronizers are used on first through fourth gear
- Reverse lock-out feature prevents accidental engagement
- Advanced clutch torsion mechanism reduces gear noise
- Helical gear limited-slip differential reduces wheel spin and maximizes acceleration
*Preliminary EPA mileage estimates determined by Honda. Final EPA mileage estimates were not available at the time of printing. Use for comparison purposes only. Actual mileage may vary.
5-Speed Sequential SportShift Automatic Transmission
- Quick-response Sequential SportShift allows semi-manual operation
- Coordination between Drive-by-Wire Throttle System and transmission makes for quicker, smoother shifts
- New, intuitive 5-position shift gate
- Advanced shift-hold control limits Up-Shift during aggressive driving mode
- Lockup torque converter design for superior fuel economy
- Advanced Grade Logic Control System reduces gear "hunting" when driving on steep hills
- Linear solenoid direct-acting control reduces shift shock and improves smoothness
Noise, Vibration & Harshness (NVH)
- Highly rigid aluminum-alloy block with cast-in iron cylinder liners
- Automatically tensioned, maintenance free serpentine accessory drive
- 60-degree V-angle for inherently smooth operation
- Dual-mass flywheel (6 MT) reduces driveline noise and vibration
ENGINE ARCHITECTURE
The TL 3.2-liter VTEC V-6 builds on the technology of the 3.2 TL
Type-S engine that preceded it, and incorporates many refinements and
improvements. This 24-valve, 3.2-liter V-6 features aluminum-alloy
construction and has a compact, smooth firing 60-degree V-angle. A
cold-air induction system coupled with Acura's sophisticated
dual-stage intake manifold, 3-rocker VTEC system, increased
compression ratio, new close-coupled catalytic converters and high
flow exhaust delivers the highest horsepower in its class, combined
with exceptional smoothness and extremely low emissions.
ENGINE BLOCK
The new lightweight die-cast aluminum-alloy block has cast-in place
iron cylinder liners. These thin-wall liners are made using a
centrifugal spin casting process that ensures high strength and low
porosity. With rough outer surfaces, these liners bond securely to
the surrounding aluminum, enhancing liner-to-block rigidity and heat
transfer. For rigid crankshaft support and minimized noise and
vibration, the block incorporates a deep-skirt design with four bolts
per bearing cap. The block assembly is also heat-treated for greater
strength.
CRANKSHAFT/ PISTONS/CONNECTING RODS
The new crankshaft is based on that of the TL Type-S. The
counterweights have been adjusted to accommodate the new, slightly
heavier high compression pistons. With taller, reinforced crowns,
these new pistons reduce the squish volume (the mixture trapped
between the pistons and the cylinder head) and raise the compression
ratio (relative to the Type-S) from 10.5:1 to 11.0:1. The forged
steel connecting rods carry over from the Type-S.
CYLINDER HEADS / VALVES
New cylinder heads are an important factor in improving power and
emissions performance. A key feature of the cylinder heads is the
integrated exhaust manifold that is part of the cylinder head
casting. Made of pressure-cast, low-porosity aluminum, the heads help
keep overall engine weight down. Each cylinder head feeds directly
into a close-coupled catalyst. To ensure positive sealing, the TL
applies a three-layer type head gasket like that of the MDX
sport-utility vehicle and NSX. A single Aramid-fiber reinforced belt
drives the overhead camshafts.
VTEC™ (VARIABLE TIMING & LIFT ELECTRONIC CONTROL)
Acura VTEC™ (Variable Timing and Lift Electronic Control) gives
the TL engine strong low speed torque and response coupled with
class-leading high rpm horsepower. The TL VTEC system has two
distinct modes of operation for the engine's 12 intake valves. At low
speeds, the intake valves have low lift and are open a comparatively
short period of time during cylinder filling. At high rpm where
breathing is critical, the valves switch to high-lift, long duration
mode to deliver the best volumetric efficiency possible. The VTEC
changeover point occurs at 4700 rpm, and takes just 0.1 second; it's
undetectable to the driver.
In the new TL, the VTEC system continues to be the 3-rocker type, which allows each of a given cylinder's intake valves to be controlled by its own low-speed cam lobe. (By comparison, with 2-rocker VTEC, both intake valves in a given cylinder are controlled by a single low-speed cam lobe). With different low-speed cam profiles for each intake valve, 3-rocker VTEC allows for staggered valve opening and lift. This promotes swirl in the combustion chambers, which improves efficiency. With better mixing in the cylinders, burn speed and combustion stability are improved. When engine rpm reaches 4700 rpm, the powertrain control module (PCM) triggers the opening of an electric spool valve that routes pressurized oil to small pistons in the intake valve rocker arms. These pistons slide into position to lock together the three intake rockers in a given cylinder, which then follow a single high-lift, long-duration cam lobe. With the engine's intake valve lift and opening duration continuously adjusted to suit the operating engine speed, the TL benefits with a broad torque curve and superior peak power.
COLD-AIR INDUCTION SYSTEM
Cool air is denser than hot air and allows an engine to make more
power by packing more oxygen per given volume. To capitalize on this
fact, the TL has a special cold-air induction system as standard
equipment. Ambient air is picked up through an inlet in the left
front fascia, and fed by a duct to the engine air intake. Depending
on vehicle speed, this system supplies the engine with ambient air
that is much as 15 degrees F. cooler than typical engine compartment
air.
A new low-restriction induction system improves breathing in the new TL. In addition to providing more aggressive sound under acceleration, this new system flows 40 percent more air than the system in the '03 TL, and about four percent more than in the '03 Type-S.
DUAL-STAGE INTAKE MANIFOLD
Like the previous TL Type-S and the MDX, the new TL has a dual-stage
intake manifold. Working in concert with VTEC, this manifold improves
low-speed torque without sacrificing high rpm power. The manifold is
divided into two banks with three cylinders fed by each bank. The
powertrain control module (PCM) controls butterfly valves between
each bank. At low engine speeds the valves are closed; each separate
bank of the manifold is tuned to maximize the resonance effect of the
incoming air and increase cylinder filling and the torque through the
lower part of the engine's rpm range.
As the engine rpm rises, the resonance effect fades, and the butterfly valves connecting the two banks of the intake manifold open. Now the resonance from individual pressure pulsations is eliminated, and an inertia affect helps the mass of air rushing down each intake passage. This provides more charge than each cylinder would normally ingest, working like mild supercharging to enhance horsepower at high engine speeds. The manifold changeover rpm is set somewhat lower in the rpm range than is the VTEC changeover rpm. This works to smooth and broaden the torque delivery. More than 75 percent of the peak torque is available from 2100 rpm to 6500 rpm.
DIRECT IGNITION AND DETONATION-KNOCK CONTROL
Optimum ignition spark timing is crucial to engine power and
efficiency, and varies based on the engine's load, rpm, temperature
and other factors. The powertrain control module (PCM) monitors
engine functions to determine the best spark timing. An engine block
mounted acoustic detonation-knock sensor "listens" to the engine;
based on this input, the PCM retards the ignition timing
incrementally to prevent potentially damaging detonation.
Platinum-tipped sparkplugs are applied, each with an individual coil
unit positioned above in the access bore, and require no service
prior to 105,000 miles.
PROGRAMMED FUEL INJECTION (PGM-FI)
The Programmed Fuel Injection (PGM-FI) system tracks several engine
inputs including throttle position, intake air temperature, water
temperature, intake manifold pressure, etc. and monitors the exact
state of the exhaust gas. Based on these inputs PGM-FI knows when to
trigger and how long to keep open the high efficiency multi-hole
injectors that deliver fuel to each cylinder.
DRIVE-BY-WIRE THROTTLE CONTROL SYSTEM™
Like the TSX sports sedan, the new TL engine has an advanced
Drive-by-Wire Throttle System (DBW) technology that eliminates the
need for a conventional throttle cable. With the driver's throttle
pedal movements interpreted electronically, the precise relationship
between pedal movement and throttle butterfly valve opening can be
varied to suit the driving conditions. By altering the amount of
"gain" between the pedal and butterfly valve, significant
improvements in drivability are possible. DBW also allows the
Sequential SportShift automatic transmission and Vehicle Stability
Assist (VSA) with traction control to be fully integrated with engine
function.
The DBW system monitors various parameters such as pedal position, throttle position, road speed, engine speed and gear position. These inputs are then used to set the moment-to-moment relationship between the pedal position and throttle butterfly opening. In low-speed driving, the system has relatively little gain, so that engine response is smooth and progressive for smooth launches from a standing start. At higher speeds, the gain progressively increases to provide confident acceleration for passing and climbing hills.
HIGH-FLOW EXHAUST SYSTEM WITH CLOSE-COUPLED CATALYZERS
To reduce weight and move the engine's two primary catalytic
converters as close as possible to the combustion chambers, the TL
exhaust manifolds are cast right into the cylinder heads. A 900-cell
per-square-inch high efficiency converter mounts directly to the
exhaust port of each cylinder head for extremely rapid converter
light off after the engine starts. This mounting system has the added
benefit of eliminating traditional exhaust header pipes, which saves
a total of 17.6 pounds.
To ensure optimum flow and reduce backpressure, a new hydroformed 2-into-1 collector pipe carries spent gases down to a 350 cell-per-inch secondary converter under the passenger cabin. A new design for the exhaust system downstream of the secondary catalyst, including the dual silencers, further reduces back pressure and is 11 percent lighter than the comparable Type-S arrangement. Because these smaller silencers are easier to package, the rear of the new TL has a more refined appearance, finished by dual trapezoidal exhaust outlets that are tightly integrated into the rear fascia.