2008 Honda Accord - Powertrain

8/21/2007 12:25:00 PM

Overview

A total of four engines are available in the 2008 Accord family - a pair of inline four-cylinder engines and two V-6 engine choices. The base engine is a 2.4-liter i-VTEC inline four-cylinder powerplant in the LX Sedan and LX-P Sedan. With 177 horsepower, this engine delivers an increase of 7% in horsepower compared to its predecessor, while operating on regular unleaded fuel (as before). The highly-efficient power plant meets Partial Zero Emissions Vehicle (PZEV) (AT only) or ULEV-2 emissions standards* and delivers EPA-estimated City/Highway fuel economy of 21/311 mpg (Sedan AT). In total, the new Accord's base engine is more powerful, cleaner and more fuel-efficient2 than the engine it replaces.

In the Accord LX-S Coupe and all EX and EX-L models, an even more powerful inline four-cylinder engine is standard. With a high-flow muffler and reprogrammed Powertrain Control Module (PCM), the 2.4-liter inline four-cylinder generates 190 horsepower at 7000 rpm and 162 lb-ft. of torque at 4400 rpm. Though it's by far the most powerful four-cylinder engine ever offered in a North American Accord, this powerplant is designed to run on regular unleaded fuel, and also meets PZEV (AT only) or ULEV-2 emissions standards.* With a 5-speed automatic transmission, it also delivers EPA-estimated City/Highway fuel economy of 21/31(1) mpg (Sedan AT) using the new 2008 EPA methodology. That makes it just as fuel efficient as the less-powerful four-cylinder engine found in the LX and LX-P Sedan.

Both four-cylinder engines are certified as PZEV in California, Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island and Vermont. Fuel economy ratings and horsepower are unchanged, but these engines comply with tougher PZEV requirements, in part, by virtue of a special i-VTEC system that leaves one exhaust valve closed in each cylinder at low rpm, and the use of new fuel injector and dual probe spark plugs that improve combustion, in addition to the near-zero evaporative emissions equipment.

* In states that adhere to California Air Resource Board (CARB) emissions standards. All engines meet Federal Tier-2/Bin 5 emissions standards. 1Estimates reflect new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.

Four-Cylinder Engine Competitive Comparison

2008 Honda
Accord EX Sedan
2007 Toyota
Camry SE Sedan
2007 Nissan
Altima 2.5 S
Engine DOHC i-VTEC®
inline 4-cylinder
DOHC VVT-i
inline 4-cylinder
DOHC CVTCS
inline 4-cylinder
Displacement 2354cc (2.4-liter) 2362cc (2.4-liter) 2488cc (2.5-liter)
Horsepower** @ rpm 190 @ 7000 158 @ 6000 175 @ 5600
Torque** @ rpm (lb-ft.) 162 @ 4400 161 @ 4000 180 @ 3900
Transmission 5AT 5AT CVT AT
Fuel grade Regular Unleaded Regular Unleaded Regular Unleaded
2008 EPA estimated fuel
economy, City/Hwy (AT)
21/311 21/302 23/312

** SAE J1349 testing method.

(1) Estimates reflect new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.
(2) Estimated fuel economy for 2007 model using 2008 method.
Source: http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp

Accord Sedan and Coupe V-6 models equipped with 5-speed automatic transmissions are powered by a 3.5-liter i-VTEC V-6 that is the most powerful engine ever offered in a Honda vehicle. It features a new generation of Honda's advanced Variable Cylinder Management (VCM) variable displacement technology with a special SOHC i-VTEC valvetrain that allows it to operate in three different modes. Depending on driving conditions, the engine operates on three, four or all six cylinders to help boost fuel economy or power as needed.

With a 16% increase in displacement compared to the previous 3.0-liter Accord V-6, this new powerplant delivers 268 horsepower at 6200 rpm and 248 lb-ft. of torque at 5000 rpm, operating on regular unleaded fuel. That is a 10% increase in horsepower and a substantial 18% boost in torque as compared to the previous V-6.

V-6 Engine Competitive Comparison

2008 Honda Accord
EX V-6 Sedan
2007 Toyota Camry
LE V-6 Sedan
2007 Nissan Altima
3.5 SE V-6 Sedan
Engine SOHC i-VTEC®
V-6 with VCM
DOHC VVT-i
V-6
DOHC CVTCS
V-6
Displacement 3471cc (3.5-liter) 3456cc (3.5-liter) 3490cc (3.5-liter)
Horsepower** @ rpm 268 @ 6200 268 @ 6200 270 @ 6000
Torque** @ rpm (lb-ft.) 248 @ 5000 248 @ 4700 258 @ 4400
Transmission 5AT 6AT CVT AT
Fuel grade Regular Unleaded Regular Unleaded Regular Unleaded
2008 EPA estimated fuel
economy, City/Hwy (AT)
19/29 19/28 20/26

** SAE J1349 testing method.

(1) Estimates reflect new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.
(2) Estimated fuel economy for 2007 model using 2008 method.
Source: http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp

The Accord V-6 meets PZEV (AT only) or ULEV-2 emissions standards.* Though it is larger and more powerful than any engine ever offered in Accord, the V-6 returns EPA-estimated 19/291 City/Highway fuel economy, using the 2008 EPA methodology. That makes it more fuel efficient than the smaller, less powerful engine it replaces when 2007 and 2008 models are tested using the identical 2008 EPA fuel economy evaluation parameters.

* In states that adhere to California Air Resource Board (CARB) emissions standards. All engines meet federal Tier 2/Bin 5 emissions standards.

The Accord EX-L V-6 Coupe with 6-speed transmission has a unique variant of the Accord V-6 that uses VTEC valve gear without VCM to achieve enhanced low- and midrange performance. This engine has the same peak horsepower and torque as the i-VTEC VCM engine, and meets ULEV-2 emissions standards. It is paired with a close-ratio 6-speed manual transmission for maximum performance and driving control.

Engine Availability


LX/LX-S Sedan EX, EX-L Sedan;
LX, EX.
EX-L Coupe
EX V-6,
EX-L V-6 Sedan;
EX V-6. EX-L V-6 Coupe
EX-L V-6
6-Speed Coupe
Engine DOHC i-VTEC® inline 4-cylinder DOHC i-VTEC® inline 4-cylinder SOHC i-VTEC® V-6 with VCM SOHC VTEC®
V-6
Displacement 2354cc (2.4-liter) 2354cc (2.4-liter) 3471cc (3.5-liter) 3471cc (3.5-liter)
Compression ratio 10.5:1 10.5:1 10.5:1 10.5:1
Horsepower** @ rpm 177 @ 6500 190 @ 7000 268 @ 6200 268 @ 6200
Torque** @ rpm (lb-ft.) 161 @ 4300 162 @ 4400 248 @ 5000 248 @ 5000
Transmission 5 MT/5AT 5 MT/5AT 5AT 6MT
2008 EPA estimated
fuel economy, City/Hwy 1
21/31 (Sedan AT)
21/30 (Coupe AT)
22/31 (MT)
21/31 (Sedan AT)
21/30 (Coupe AT)
22/31 (MT)
19/29 (Sedan)
19/28 (Coupe)
17/25
Theoretical 2007 EPA
estimated fuel economy,
City/Hwy 2
24/34 (Sedan AT)
24/33 (Coupe AT)
25/34 (MT)
24/34 (Sedan AT)
24/33 (Coupe AT)
25/34 (MT)
22/32 (Sedan)
20/31 (Coupe)
18/27
Fuel type Regular unleaded Regular unleaded Regular unleaded Regular unleaded
Emissions certification (CARB/EPA) ULEV-2/PZEV ULEV-2/PZEV ULEV-2/PZEV ULEV-2

** SAE J1349 testing method.

(1) Estimates reflect new EPA fuel economy methods beginning with 2008 models. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle.
(2) Source: http://www.fueleconomy.gov/feg/calculatorSelectYear.jsp

Powertrain Features at A Glance

2.4-liter Inline 4-cylinder Engine (LX, LX-P Sedan)

  • 2.4-liter, DOHC, i-VTEC® inline four-cylinder engine
  • 177 horsepower at 6500 rpm
  • 161 lb-ft. of torque at 4300 rpm
  • i-VTEC® (Variable Valve Timing and Lift Electronic Control) + VTC (Variable Timing Control)
  • EPA-estimated fuel economy of 21/31 mpg (AT Sedan) City/Highway1
  • Regular unleaded fuel
  • Direct ignition system
  • Drive-by-Wire Throttle System™
  • 5-speed automatic (available) or 5-speed manual transmissions
  • Close-coupled catalytic converter plus under-floor catalytic converter
  • ULEV-2 emissions compliant
  • PZEV (AT only) version sold in California, Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island and Vermont
  • Dual-probe spark plugs
  • Unique i-VTEC system provides single exhaust valve operation at low rpm

2.4-liter Inline 4-cylinder Engine (EX, EX-L Sedan; LX-S, EX, EX-L Coupe)

  • 2.4-liter, DOHC, i-VTEC® inline four-cylinder engine
  • 190 horsepower at 7000 rpm
  • 162 lb-ft. of torque at 4400 rpm
  • i-VTEC® + VTC
  • EPA estimated fuel economy of 22/31 mpg (MT) City/Highway1
  • Regular unleaded
  • Direct ignition system
  • Drive-by-Wire Throttle System™
  • 5-speed automatic or 5-speed manual
  • Close-coupled catalytic converter plus under-floor catalytic converter
  • ULEV-2 emissions compliant
  • PZEV (AT only) version sold in California, Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island and Vermont
  • Dual-probe spark plugs
  • Unique i-VTEC system provides single exhaust valve operation at low rpm

V-6 Engine with Automatic Transmission (EX V-6, EX-L V-6 Sedan; EX V-6. EX-L V-6 Coupe)

  • 3.5-liter, SOHC, i-VTEC® V-6
  • 268 horsepower at 6200 rpm
  • 248 lb-ft. of torque at 5000 rpm
  • i-VTEC® provides Variable Cylinder Management (VCM) for fuel efficiency
  • Magnesium intake manifold and valve cover
  • Close-coupled catalytic converters plus under-floor catalytic converter
  • EPA estimated fuel economy of 19/29 (Sedan), 19/28 (Coupe) mpg City/Highway1
  • Regular unleaded
  • Direct ignition system
  • Drive-by-Wire Throttle System™
  • 5-speed automatic
  • ULEV-2 emissions compliant
  • PZEV version sold in California, Connecticut, Maine, Massachusetts, New York, Rhode Island and Vermont
  • Dual-probe spark plugs

V-6 Engine with Manual Transmission (EX-L V-6 6-Speed Coupe)

  • 3.5-liter, SOHC, VTEC® V-6
  • 268 horsepower at 6200 rpm
  • 248 lb-ft. of torque at 5000 rpm
  • VTEC® with variable intake manifold provides two intake cam profiles for enhanced low- and mid-range torque
  • Close-coupled catalytic converters plus under-floor catalytic converter
  • ULEV-2 emission compliant
  • EPA estimated fuel economy of 17/25 mpg City/Highway1
  • Regular unleaded
  • Direct ignition system
  • Drive-by-Wire Throttle System™
  • 6-speed manual

Shared Engine Features

The following engine technologies are shared among all 2008 Accord models unless noted.

i-VTEC (all except Accord V-6 6MT Coupe)
Though the Accord four-cylinder engines and the V-6 with automatic transmission are all called i-VTEC powerplants, it is important to note that the details in each application differ. Honda's four-cylinder engines have double overhead camshafts (DOHC) and i-VTEC that is comprised of VTEC + Variable Timing Control (VTC) of the intake camshaft for optimized power production and fuel efficiency. In addition, PZEV variants also idle one of the two exhaust valves in each cylinder at low rpm for enhanced emissions performance. Accord V-6 engines (with the automatic transmission) use a Single Overhead Camshaft (SOHC) design that features i-VTEC with Variable Cylinder Management (VCM) to maximize fuel economy.

Dual-Probe Spark Plugs
The Accord's 4-cylinder and V-6 PZEV-compliant engine uses special dual-probe spark plugs (a first for Honda in North America) for faster mixture ignition speed and improved combustion stability. With the spark arcing just beyond the relatively large surface of the ground area, the air/fuel mixture is exposed to a larger portion of the spark, which enhances stable combustion.

Drive-By-Wire (DBW) Throttle System™
The Accord's drive-by-wire throttle system uses smart electronics instead of a conventional cable system to connect the throttle pedal to the throttle butterfly in the intake tract. Besides allowing engineers to program the relationship between throttle pedal movement and engine response, the system offers optimizes engine response to suit driving conditions. The system monitors throttle pedal position, throttle butterfly position, road speed, engine speed and engine vacuum. This information is used to define the throttle control sensitivity.

Programmed Fuel Injection (PGM-FI)
The Accord's PGM-FI continually adjusts the fuel delivery to yield the best combination of power, low fuel consumption and low emissions. Multiple sensors constantly monitor critical operating parameters, such as throttle position, intake air temperature, coolant temperature, ambient air pressure, intake airflow volume, intake manifold pressure, exhaust air-fuel ratio and the position of the crankshaft and cams.

Direct Ignition System
All Accord engines use direct ignition, which has a coil unit for each cylinder, positioned within each spark plug's access bore.

Fuel Injectors
The Accord engine's fuel injector nozzles reduce the typical size of fuel droplets by 34 percent compared to the 2007 model, which improves atomization and flame propagation inside the combustion chambers. The better atomization enhances combustion and reduces emissions.

High-Efficiency Catalytic Converters
Key contributors to the Accord engine's excellent emissions performance are its high-efficiency catalytic converters. All engines have their exhaust manifold(s) cast directly into the aluminum alloy cylinder head(s) to reduce weight and position each primary catalytic converter as close as possible to the combustion chambers. A high-efficiency close-coupled converter mounts directly to the exhaust port of each cylinder head for extremely rapid converter activation after engine startup. A second converter is positioned shortly downstream, beneath the passenger compartment floor. Both converters use a new thin-wall design that increases internal reaction area and improves efficiency.

Maintenance Minder System and Tune-Up Intervals
The Accord's standard Maintenance Minder system calculates the engine's tune-up schedule based on driving conditions (tracked by the ECU). When determining proper maintenance intervals, the system minimizes owner guesswork about whether the vehicle is being operated in standard or severe conditions. The Accord's Maintenance Minder information appears in the odometer display, and indicates when to change the oil, oil filter (every other oil change), air cleaner, transmission fluid, spark plugs and coolant, as well as when to rotate the tires. A tune-up is not required until 100K+/- Miles No Scheduled Tune-ups (may vary with driving conditions. Does not apply to fluid and filter changes. Exact mileage is determined by actual driving conditions. The owner's manual contains full detail).

Regular Unleaded Fuel Operation
To keep operating costs at a minimum, all Accord models are designed to use relatively less-expensive regular unleaded fuel, thanks to compact 4-valve combustion chambers and precise fuel injection and spark control.

177 Horsepower 2.4-liter Inline 4-cylinder Engine (LX, LX-P Sedan)

Overview
A 2.4-liter DOHC i-VTEC four-cylinder engine that develops 177 horsepower and 161 lb-ft. of torque powers the LX and LX-P Accord Sedans. This clean-running engine meets PZEV (AT only) emissions standards in select states, or Federal Tier 2, Bin 5 standards in all states. It delivers EPA-estimated 21/311 mpg City/Highway fuel economy (Sedan AT).

Engine Block and Crankshaft
Accord's 2.4-liter engine has a die-cast aluminum block with a single main-bearing cradle design that creates a rigid assembly to help minimize noise and vibration. Centrifugal spin cast iron cylinder liners provide long lasting durability. Each journal on the forged-steel crankshaft is micropolished to reduce internal friction.

Cylinder Head and Valvetrain
The Accord four-cylinder engine has a lightweight cylinder head that is made of pressure-cast aluminum alloy. A silent-chain drives dual overhead cams and four valves per cylinder. The cam drive is maintenance free throughout the life of the engine.

i-VTEC Valve Control System
The Accord's 2.4-liter, DOHC, 16-valve i-VTEC engine uses an advanced valve-control system to combine high power output with high fuel efficiency and low emissions. The Accord system combines Variable Timing Control (VTC), which continuously adjusts the intake camshaft phase, with Variable Valve Timing and Lift Electronic Control (VTEC), which changes valve lift, timing and duration of the intake valves.

At low rpm, the VTEC intake valve timing and lift are optimized for rapid swirl-pattern cylinder filling. As engine rpm builds past 5000 rpm, the VTEC system transitions to a high-lift, long-duration intake cam profile for superior high-rpm engine power.The "intelligent" portion of the system is its ability to continuously vary the timing of the intake cam relative to that of the exhaust camshaft. This helps boost power and also provides a smoother idle (allowing idle speed to be reduced). The intake cam timing is varied based on input from sensors that monitor rpm, timing, throttle opening, cam position and exhaust air-fuel ratio. The result is increased fuel economy and lower NOx emissions.

PZEV Version
A PZEV version of the 177- and 190-horsepower four-cylinder engines is sold in California, Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island and Vermont. The principal differences between the PZEV Accord and the ULEV-2 version sold in all states are single exhaust valve operation at low rpm, special dual-probe spark plugs and remapped Powertrain Control Module (PCM) programming, in addition to the near-zero evaporative emissions equipment. The horsepower, torque and EPA-estimated fuel economy of the PZEV and ULEV-2 engines are identical.

Single Exhaust Valve Operation
The Accord's 2.4-liter DOHC i-VTEC PZEV-compliant engine has two modes of exhaust valve operation. Below 2500 rpm, only one exhaust valve operates, creating a strong rotational flow in the exhaust gases that creates a "thermal reactor" effect to reduce hydrocarbon emissions. Above 2500 rpm where exhaust flow increases, a hydraulically actuated pin locks the rockers for both exhaust valves together so they operate in unison, following a single cam profile.

190 Horsepower 2.4-liter Inline 4-Cylinder Engine (EX, EX-L Sedan; All Coupes)

Overview
The 2.4-liter inline four-cylinder engine that powers the EX, EX-L Sedan and LX-S, EX and EX-L Coupe is closely related to the engine in the LX Sedan and LX-P Sedan. The 190-horsepower inline four-cylinder meets ULEV-2 in all states, and PZEV (AT only) emissions standards in select states. Like the 177-horsepower engine, the 190-horsepower engine's PZEV variant has single exhaust valve operation at low rpm, dual-probe electrode spark plugs and special PCM mapping.

The key feature that allows this engine to make an additional 13 horsepower and 1 lb-ft. of torque compared to the 177-horsepower four-cylinder engine is a special exhaust system with larger diameter tubing and a variable-valve silencer design that nets a 31% increase in flow relative to the previous generation Accord four-cylinder system. Despite its performance advantage, this engine delivers the same EPA-estimated 21/311 City/Highway fuel economy (Sedan AT) as its less powerful counterpart. Inside the interior of 190-horsepower Accord models, an Active Noise Control system (ANC) helps reduce certain undesirable sound frequencies for greater passenger comfort. (Please see the Interior tab for more information.)

268 Horsepower 3.5-liter i-VTEC V-6 (EX V-6, EX-L V-6 Sedan; EX-L V-6 Coupe)

Overview
The 3.5-liter SOHC i-VTEC V-6 engine available in the Accord Sedan and Coupe is the largest and most powerful engine ever offered in a Honda passenger car. It builds on technologies that have been developed and refined on previous Honda powerplants. With its 60-degree V-angle, the Accord's V-6 engine is inherently very smooth and has compact overall dimensions that allow efficient packaging within the vehicle. The V-6 with automatic transmission incorporates a new-generation of i-VTEC technology that boosts fuel efficiency using Variable Cylinder Management (VCM).

Engine Block and Crankshaft
The Accord's available V-6 has a die-cast lightweight aluminum alloy block with cast-in-place iron cylinder liners. Made with a centrifugal spin casting process, the thin-wall liners are high in strength and low in porosity. The block incorporates a deep-skirt design with four bolts per bearing cap for rigid crankshaft support and minimized noise and vibration. Both the block and caps are heat treated for greater strength.

Cylinder Heads/Valvetrain
Like other Honda V-6 powerplants, the Accord V-6 cylinder heads are a single-overhead-camshaft design, with the cams driven by the crankshaft via an automatically tensioned toothed belt. Made of low-pressure cast, low-porosity aluminum, each cylinder head incorporates an integrated exhaust manifold to reduce parts count, improve flow and optimize the location of the close-coupled catalyst on each cylinder bank.

i-VTEC with 3-stage Variable Cylinder Management™ (VCM™)
The Accord's available SOHC V-6 with automatic transmission includes i-VTEC with VCM. With the boost in fuel efficiency attributable to VCM, the larger and more powerful Accord V-6 with automatic transmission actually gets better fuel economy than its smaller, less powerful predecessor when tested with the same methodology. Using the EPA's new 2008 methodology, the Accord V-6 Sedan returns EPA-estimated fuel economy of 19/29 City/Highway. That is an increase over the previous Accord V-6 (18/26 City/Highway) of 1 mpg City/3 mpg Highway, when both vehicles are compared with the same 2008 methodology.

VCM Operation
To help improve the fuel efficiency of the V-6 engine available with the 5-speed automatic transmission, a new generation of Honda's VCM is used. This is the first application of VCM on a non-hybrid Accord model. Unlike previous VCM systems that switched between three- and six-cylinder operation, the Accord's system can operate on three, four or all six cylinders.

During startup, acceleration or when climbing hills - any time high power output is required - the engine operates on all six cylinders. During moderate speed cruising and at low engine loads, the system operates just one bank of three cylinders. For moderate acceleration, higher-speed cruising and mild hills, the engine operates on four cylinders.

With three operating modes, the VCM system can finely tailor the working displacement of the engine to match the driving requirements from moment to moment. Since the system automatically closes both the intake and exhaust valves of the cylinders that are not used, pumping losses associated with intake and exhaust are eliminated and fuel economy gets a further boost. The VCM system combines maximum performance and maximum fuel economy - two characteristics that don't typically coexist in conventional engines.

VCM deactivates specific cylinders by using the VTEC (Variable Valve-Timing and Lift Electronic Control) system to close the intake and exhaust valves while simultaneously the Powertrain Control Module cuts fuel to those cylinders. When operating on three cylinders, the rear cylinder bank is shut down. When running on four cylinders, the left and center cylinders of the front bank operate, and the right and center cylinders of the rear bank operate.

The spark plugs continue to fire in inactive cylinders to minimize plug temperature loss and prevent fouling induced from incomplete combustion during cylinder re-activation.

The system is electronically controlled, and uses special integrated spool valves that do double duty as rocker-shaft holders in the cylinder heads. Based on commands from the system's electronic control unit, the spool valves selectively direct oil pressure to the rocker arms for specific cylinders. This oil pressure in turn drives synchronizing pistons that connect and disconnect the rocker arms.

The VCM system monitors throttle position, vehicle speed, engine speed, automatic-transmission gear selection and other factors to determine the correct cylinder activation scheme for the operating conditions. In addition, the system determines whether engine oil pressure is suitable for VCM switching and whether catalytic-converter temperature will remain in the proper range. To smooth the transition between activating or deactivating cylinders, the system adjusts ignition timing, drive-by-wire throttle position and turns the torque converter lock-up on and off. As a result, the transition between three-, four-, and six-cylinder operation is unnoticeable to the driver.

Active Control Engine Mount (ACM) and Active Noise Control (ANC)
The ACM system is used to minimize the effects of engine vibration as the VCM system switches cylinders on and off. Sensors alert the Electronic Control Unit (ECU) to direct ACM actuators positioned at the front and rear of the engine to move to cancel engine vibration. Inside the interior of the Accord, the ANC system works in cooperation with the ACM system to further reduce any sound relating to the function of the VCM system. (Please see the Interior tab for more information.)

V-6 High-Flow Exhaust System
The Accord V-6 has a completely new exhaust system to accommodate its larger displacement and increased power output. Tubing diameter has been increased and new dual silencers are used. In total, the changes provide a 38% increase in exhaust flow compared to the previous V-6 system.

3.5-liter VTEC V-6 (Manual Transmission EX-L V-6 6MT Coupe)

Overview
The Accord V-6 Coupe with 6-speed manual transmission uses a unique version of the 3.5-liter V-6. In place of the i-VTEC cylinder heads that incorporate Variable Cylinder Management (VCM) technology for enhanced fuel economy, the performance-oriented 6-speed V-6 Coupe has VTEC cylinder heads that operate all six cylinders under all driving conditions. The engine switches between two different intake valve profiles based on the operating conditions to deliver superior low- and mid-range power, while achieving the same peak 268 horsepower and 248 lb-ft. torque figures found in the automatic transmission version with VCM. The engine also features a variable intake manifold (constructed of lightweight magnesium) to improve low- to mid-range torque.

VTEC® (Variable Valve Timing and Lift Electronic Control)
VTEC® operates the engine's 12 intake valves in two distinct modes. At low engine speeds, the intake valves follow low lift and relatively short duration cam profiles. At high engine speeds the valves switch to high-lift, long-duration mode to deliver the best volumetric efficiency. The V-6 with 6-speed manual transmission has a VTEC changeover point that occurs at approximately 5000 rpm.

Intake and Exhaust Tuning
The intake and exhaust systems on the Accord Coupe V-6 with six-speed manual transmission feature exclusive intake and exhaust tuning for sporty sounding performance. The intake is designed to resonate a unique performance sound at mid and high rpms, while the exhaust is designed to convey a low, powerful note at low to mid rpm.

Transmissions

5-Speed Manual Transmission
A lightweight, compact 5-speed manual transmission is available with either the 177- or 190-horsepower Accord four-cylinder engine. Housed in a rigid die-cast aluminum case, the transmission uses multi-cone synchronizers on first through fourth gears that contribute to a smooth, fluid shift feel. A single plate clutch with a diaphragm-type spring provides smooth, progressive engagement combined with low pedal effort.

Close-Ratio 6-Speed Manual Transmission
While most Accord V-6 models have a 5-speed automatic transmission, the EX-L V-6 Coupe is also available with a close-ratio 6-speed manual transmission. This short-throw unit is designed to take advantage of the high power and torque of the new Accord V-6 engine and give enthusiast drivers maximum control.

Substantially lighter than the automatic transmission, the 6-speed manual features a high-pressure die-cast aluminum-alloy transmission housing to save weight. High-strength steel gears are used, and the shafts are hollow, netting a further reduction in weight.

Closely spaced ratios help provide stronger acceleration by keeping engine revs up closer to the engine's horsepower peak. A reverse lockout feature prevents the transmission from accidentally being shifted into reverse while the car is moving forward.

The Accord's manual transmission is matched with a compact clutch unit that is self-adjusting for consistent pedal stroke and load throughout its service life. A dual-mass flywheel cuts down the transfer of engine vibration into the cabin and provides increased comfort during shifting and helps to reduce noise.

5-Speed Automatic Transmission
Accord four-cylinder and V-6 models are available with 5-speed automatic transmissions with Grade Logic Control. Four-cylinder engines have a compact three-shaft transmission design that is engineered for smooth operation and fuel efficiency. To accommodate the large displacement and high power output of the Accord V-6 engine, a four-shaft, 5-speed automatic transmission related to the transmission used in the Honda Odyssey is used.

Accord's Powertrain Control Module (PCM) manages overall powertrain operation, and provides precise management of the interaction between automatic transmission and engine. This integrated control strategy makes for smoother shifts with reduced shift shock. VCM engines are equipped with a long torsional control damper to helps enhance overall transmission smoothness.

Different transmission gear ratios are used for the 177-horsepower and 190-horsepower four-cylinder engines. To take full advantage of the 190-horsepower engine's added high-rpm power, its 5-speed automatic transmission has lower second-, third- and fourth-gear ratios (higher numerically). This provides an added boost to acceleration and responsiveness. The first- and the fifth-gear ratios are common among all four-cylinder engines, resulting in an efficient and quiet cruising rpm at higher speeds.

Grade Logic Control
To reduce gear "hunting" and unnecessary shifting, Grade Logic Control and Shift Hold Control systems are integrated into the shift programming of Accord automatic transmissions. Grade Logic Control alters the 5-speed automatic's shift schedule, reducing shift frequency while traveling uphill or downhill. Using inputs monitoring throttle position, vehicle speed and acceleration/deceleration, Grade Logic compares the operating parameters with a digital map stored in the transmission computer. When the system determines the Accord is on a hill, the shift schedule is adjusted to automatically hold the transmission in a lower gear for better climbing power or increased downhill engine braking.

Shift Hold Control
Shift Hold Control prevents upshifts to higher gears (fourth and fifth) in repeated winding-road situations where the throttle is quickly released and the brakes are applied. This reduces disturbance to the chassis when entering a corner, and ensures strong power is available without a downshift. Shift Hold Control improves throttle responsiveness and reduces unnecessary shifting on curving roads.