Honda Automobiles: 2016 Honda Accord Press Kit

The key feature that allows this engine to make an additional four horsepower compared to the 185-horsepower 4-cylinder engine is a special exhaust system with larger diameter tubing and dual outlets that nets a 52-percent increase in flow relative to the 185-horsepower 4-cylinder system.

3.5-liter SOHC i-VTEC V-6
The 3.5-liter V-6 engine is available in the Accord EX-L V-6 and Touring Sedan, and EX-L V-6 Coupe. The aluminum-alloy 24-valve engine produces 278 horsepower at 6200 rpm and generates 252 lb-ft. of torque at 4900 rpm, with robust torque output in the lower ranges below 4900 rpm where the engine typically operates. Design features that assist in the efficiency of the engine include optimized intake and exhaust ports, valve timing and Variable Valve Timing and Lift Electronic Control (VTEC) operation, and when equipped with automatic transmission, Variable Cylinder Management (VCM) with a wide range of operation.

The Accord V-6 has an anticipated EPA fuel economy rating of 21/34/26¹ mpg city/hwy/combined (Sedan 6AT). This fuel efficiency is possible in part due to internal friction reduction features including an oil-ring ion-plating treatment, plateau honing and optimized auxiliary-belt tension. The tumble-type intake port design improves combustion efficiency, and the torque-converter function in the available 6-speed automatic transmission aids efficient power transfer. The lighter-weight cylinder head bridge structure with separate rocker arm holders and lightweight resin cam covers further assist in overall efficiency.

Engine Block and Crankshaft
With its 60-degree V-angle, the Accord’s V-6 engine is inherently smooth and has compact overall dimensions that allow efficient packaging within the vehicle. The 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.

A new cooling control spacer positioned in the water jacket surrounding the cylinders helps to keep operating temperature and tolerances more consistent. Plateau honing further lowers the friction level between the pistons and the cylinders by creating an ultra-smooth surface. This 2-stage machining process uses two grinding processes instead of the more conventional single honing process. Plateau honing also enhances the long-term wear characteristics of the engine.

Cylinder Heads and Valvetrain
Like other Honda V-6 powerplants, the 2016 Accord V-6 engine’s 4-valve 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 a new “tumble port” design that improves combustion efficiency. An integrated exhaust manifold cast into each cylinder head reduces parts count, improves flow and optimizes the location of the close-coupled catalyst.

i-VTEC with 2-Stage Variable Cylinder Management™ (VCM™)
The Accord’s V-6 engine combines Variable Cylinder Management (VCM) (when equipped with automatic transmission) with Variable Valve Timing and Lift Electronic Control (VTEC), which changes valve lift, timing and duration of the intake valves. The switching mechanism allows each cylinder to operate with low-rpm valve lift and duration or high rpm lift and duration. When equipped with automatic transmission, the rear cylinder bank can also leave all intake and exhaust valves closed to maximize fuel efficiency during cylinder deactivation.

The “intelligent” portion of the system is its ability to vary valve operation based on the driving situation and engine rpm. At low rpm, the VTEC intake valve timing and lift are optimized for increased torque, which now allows a wider range of 3-cylinder operation (when equipped with automatic transmission). As engine rpm builds past 5150 rpm (6AT; 6MT: 4900 rpm) the VTEC system transitions to a high-lift, long-duration intake cam profile for superior high-rpm engine power. In cylinder cut-off mode (6AT models), the rear bank of intake and exhaust valves remain closed, to eliminate pumping losses.

To help with the fuel efficiency of the V-6 engine, the new generation of Honda’s Variable Cylinder Management (VCM) is used in models with an automatic transmission. The VTEC system and active engine mounts allow the VCM system to operate with three cylinders in a wide range of situations to maximize fuel efficiency, which helped lead to an anticipated EPA fuel economy rating of 21/34/26 mpg city/hwy/combined (Sedan 6AT) and lower emissions. When greater power is needed, the system switches seamlessly to 6-cylinder operation.

During startup, aggressive 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 or moderate engine loads, the system operates just the front bank of three cylinders.

The VCM system can 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 efficiency gets a further boost. The system combines maximum performance and maximum fuel efficiency – 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. 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 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 torque-induced jolt of 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 3- and 6-cylinder operation is unnoticeable to the driver.

Active Control Engine Mounts and Active Noise Control
The new-generation 28-volt Active Control Engine Mount system (ACM) is used to minimize the effects of engine vibration as the VCM system switches cylinders on and off. The powerful 28-volt ACM is a key factor in the VCM’s broader range of operation in the new Accord. 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, an Active Noise Control system (ANC) works in cooperation with the ACM system to further reduce any sound relating to the function of the VCM system.

Programmed Fuel Injection (PGM-FI)
The V-6 engine’s Programmed Fuel Injection (PGM-FI) continually adjusts 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.

Continuously Variable Transmission (CVT)
The Accord 4-cylinder’s available Continuously Variable Transmission (CVT) offers smooth and predictable gear ratio transitions and excellent acceleration matched with efficient low-rpm cruising. Available in all 4-cylinder Accord LX, Sport, EX and EX-L models, the CVT has a wide ratio spread that allows for strong acceleration performance coupled with reduced engine rpm at high road speeds and higher fuel efficiency.

The CVT is comprised of a torque converter that drives two variable-width pulleys connected by a steel belt. With its angled inner faces, the belt can circle the angled pulley faces at varying diameter depending on the pulley width, which alters the effective ratio between the pulleys. Since there are no steps in the pulley faces, the range of possible gear ratios is essentially infinite. This ultra-fine control of the gear ratio is the key to the CVT’s greater efficiency over a conventional automatic transmission with a limited number of discrete gear ratios. Instead of approximating the correct ratio for the conditions like a conventional automatic does, the Accord CVT can precisely select the optimum ratio from moment to moment without steps or slippage.

Computer control of the transmission allows the ratio between the pulleys to be altered almost instantly to best suit the driving conditions and accelerator pedal setting. A planetary gear set allows the transmission to shift between forward and reverse operation, and a variable-flow oil pump optimizes flow to the transmission’s moving parts while minimizing the load on the engine. Compared to a conventional automatic transmission, the CVT has more compact dimensions, fewer parts and a higher torque capacity.

CVT Automatic Modes
The transmission can be operated in two different fully automatic modes with the console-mounted straight-gate shifter. The D position is ideal for most driving situations, and combines fuel efficiency with smooth operation and responsive power when needed. The S position is for more performance-oriented driving, and features more aggressive transmission mapping to keep engine rpm higher for greater acceleration and response.

G-Design Shift Feature
The Accord CVT is designed to provide the optimum gear ratio for the driving conditions, and to offer a more natural driving feel than some previous CVT transmissions that may have something of a disconnected “rubber-band” feel compared to a conventional automatic transmission.

The Accord CVT has special G-design shift logic that is designed to offer more immediate acceleration response than either conventional automatics or other CVT designs. When abruptly applying power from a steady-state cruising speed, the Accord CVT immediately sends power to the drive wheels while simultaneously adjusting the gear ratio (seamlessly and progressively downshifting) to smoothly bring the engine to its horsepower peak in a linear way.

By comparison, a conventional automatic is slower to respond and loses time making multiple downshifts. Since the automatic transmission has a limited number of separate, discrete ratios, even when fully downshifted, it can only approximate the optimum engine rpm as speed increases. This reduces acceleration performance.

Compared to other CVT systems, the Accord CVT offers stronger acceleration response with a linear build in engine rpm that avoids much of the “disconnected” or “slipping” feeling some drivers notice with other CVTs. G-design shifting logic gives the Accord a more linear and sporty driving feel.

S-Position Control
To allow the driver to alter the operation of the CVT, the console-mounted gear selector includes an “S” position that provides a sport-shift schedule that delays upshifting for more available power, and provides greater engine braking.

Steering-Wheel Mounted Paddle Shifters
Whether in D or S position, special transmission logic programming allows the use of the steering-wheel-mounted paddle shifters, which are standard on the Sport (CVT) trim of the Accord Sedan and all CVT equipped Accord Coupes. When the driver operates the steering wheel-mounted paddle shifters while in Drive, the transmission responds to the driver’s shift command by selecting one of the available seven fixed ratios, and then returns to its normal fully automatic Drive mode if further paddle shift inputs are not made within a short time. This special logic makes it easy for the driver to command a quick downshift without leaving the convenience of Drive mode.

When in S position, use of the paddle shifters puts the transmission into full manual mode that remains until another mode of operation is selected with the console-mounted shifter. The paddle shifters allow the driver to select among seven fixed gear ratios. When in manual mode, if the engine’s redline is reached, the Accord will automatically shift to the next gear ratio to avoid engine damage. It will also shift down to an appropriate lower gear ratio if necessary to avoid “lugging” the engine.

Six-Speed Automatic Transmission with Grade Logic Control
To maximize driver control, acceleration and fuel efficiency, the Accord V-6 is available with a 6-speed automatic transmission featuring racing-inspired steering wheel-mounted paddle shifters and two automatic shift modes. The 6-speed automatic transmission’s layout was designed with Honda engineering prowess to optimize power flow and minimize size, parts count and overall weight. These efficiencies plus the wide torque converter lockup range contribute to the impressive EPA fuel economy ratings.

The 6-speed transmission can be controlled by a straight-gate console-mounted shifter or a steering wheel paddle shifter system (the latter standard on all Coupe models) that works whenever the transmission is in either of its two automatic modes.

The 6-speed automatic transmission also includes engineering enhancements aimed at improved performance and efficiency. Expanded multi-disc lock-up control improves the efficiency of power delivery and works with the new gear ratios to provide an improvement in fuel efficiency, as compared to a conventional design. In addition to Grade Logic Control, all of the transmission logic systems work together to automatically alter shift timing based on driving conditions.

Multi-Clutch Lock-Up Torque Converter
The 6-speed automatic transmission teams with a torque converter that has a unique converter lock-up assembly. The lock-up assembly uses multiple lock-up disks that generate nearly double the facing area of a typical torque converter. The lock-up assembly not only reduces heat build-up during operation, but also features improved overall lubrication that generates better cooling. The torque converter allows for lock-up activation during a much wider range of driving conditions for improved fuel efficiency.

Automatic Modes
The 6-speed transmission can be operated in two different fully automatic modes with the console-mounted straight-gate shifter. The D (or “Drive”) mode is ideal for most driving situations, and combines fuel efficiency with smooth operation and responsive power when needed. The S (or “Sport”) mode is for more performance-oriented driving, and features more aggressive shift mapping to keep engine rpm higher for greater acceleration and response.

In Sport mode the transmission typically operates in the four lowest gears, and it won’t shift to fifth gear unless the vehicle reaches a much higher speed. In Sport mode, the efficiency-oriented sixth gear is locked out. When in the D mode (that is optimized for normal driving), the transmission incorporates an advanced Grade Logic Control System and Shift Hold Control, which reduce unwanted shifting and gear hunting. The result is smart transmission operation that optimizes fuel efficiency and keeps the transmission in the appropriate gear for the specific driving conditions, thus generating excellent performance and smooth operation.

While traveling up or down hills, Grade Logic Control alters the transmission’s shift schedule to reduce shift frequency and improve speed control. A shift map in the transmission computer continually measures throttle position, vehicle speed and acceleration/deceleration, and then determines when the vehicle is on a hill. The shift schedule is then adjusted to hold the transmission in lower gears to boost climbing power or to provide engine braking when traveling downhill.

Shift Hold Control keeps the transmission in its current (lower) gear ratio when aggressive driving is detected, as in the case of decelerating at a corner entry. Shift Hold Control leaves the chassis undisturbed by excess shifting and ensures that power will be immediately available (without a downshift) at the corner exit.

Temporary Manual Operation
Whether in D or S mode, special transmission logic programming allows the use of the steering-wheel-mounted paddle shifters (standard on all Coupe models). When the driver operates the steering wheel-mounted paddle shifters while in D mode, the transmission responds to the driver’s shift command and then returns to its normal fully automatic D mode if further paddle shift inputs are not made within a short time. This special logic makes it easy for the driver to command a quick downshift without leaving the comfort of D mode. When in S mode, use of the paddle shifters puts the transmission into full manual mode that remains until another automatic mode of operation is selected with the console-mounted shifter.

Manual Mode
The transmission is shifted into S mode by moving the center console-mounted gear selector lever rearward to the detent labeled “S.” This mode offers automatic operation with more aggressive shift mapping. A pull on the racing-inspired, steering wheel-mounted paddle shifters (standard on all Coupe models) places the transmission in fully manual mode. A digital instrument display indicates which gear the transmission is in.

A double-kick-down feature lets the driver command a sport-minded double downshift – such as from fifth to third gear. By pulling on the left downshift paddle twice in rapid succession, the transmission will drop directly to the chosen lower gear ratio. The Drive-by-Wire™ throttle system also creates a “blip” of the throttle to help match gear speeds while downshifting.

To prevent harm to the powertrain when the transmission is paddle shifted by the driver (including during double-kick-down shifts), the system will inhibit potentially damaging shifts. As an added protective measure, the Powertrain Control Module (PCM) can also cut off engine fuel flow to prevent over-revving. If fuel cut-off is insufficient to prevent engine over-revving, as may be possible when the vehicle is on a steep downhill, the transmission will automatically upshift to prevent damage. On downshifts, the transmission will not execute a driver command that will over-rev the engine.

For improved stop-and-go performance and to prevent “lugging” the engine, the transmission will automatically downshift to first gear even though the transmission has been left in a higher gear, (except in second gear) as the vehicle comes to a stop. In Manual Mode, when coming to a stop in second gear, the vehicle will start in second gear as well.

Six-Speed Manual Transmission (4-cylinder)
On Accord Sedan models, a 6-speed manual transmission (6MT) is standard on Accord LX, Accord Sport and Accord EX. On Accord Coupe models, the 6-speed is standard on LX-S and EX. More compact than the 5-speed transmission it replaces, the unit also offers smooth and precise shift feel and greater efficiency. The transmission has been carefully engineered to deliver state-of-the-art performance and shift action, with reduced internal friction, tighter internal tolerances and improved synchronizers. The transmission also has a rigid aluminum exterior case, high-capacity ball bearings, stiff gear shafts, and high torque capacity. The design of the shift linkage and the selector mechanism reduce the sensation of play at the shift lever and smooth the shift action. A constant-mesh helical reverse gear mechanism significantly reduces noise when reverse is selected. A reverse lockout feature prevents the transmission from accidentally being shifted into reverse while the car is moving forward.

Six-Speed Manual Transmission (V-6)
The Accord EX-L V-6 Coupe is available with a 6-speed manual transmission (6MT). With closely spaced gear ratios and a short-throw shifter, the 6-speed manual is the perfect complement to the Accord V-6 Coupe’s sporting side. A lightweight aluminum transmission case and hollow gear shafts help reduce weight, while durability is ensured by high-strength gears. 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.

Accord Common Engine Features

i-VTEC Valvetrain
The Accord 4-cylinder and V-6 engines are all i-VTEC powerplants, but it’s important to note that the details in each application differ. Honda’s 4-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. Accord V-6 engines use a Single Overhead Camshaft (SOHC) design that features i-VTEC with Variable Cylinder Management (VCM) to maximize fuel efficiency.

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 or direct injection and spark control.

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 a better drivability and 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.

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.

Close-Coupled Catalyst(s)
Both inline-four and V-6 Accord engines have their exhaust manifold(s) cast directly into the aluminum alloy cylinder head(s) to reduce weight and parts count and to position each primary catalytic converter as close as possible to the combustion chambers. A high-efficiency converter mounts directly to the exhaust port of each cylinder head for extremely rapid converter activation after engine startup.