2011 Honda Odyssey: Powertrain

Summary

The 2011 Honda Odyssey comes standard with a 248-horsepower V-6 engine, a 5-speed automatic transmission on Odyssey LX, EX and EX-L, and a new 6-speed automatic transmission on the Odyssey Touring. The 3.5-liter, 24-valve SOHC i-VTEC® powerplant with Variable Cylinder Management™ (VCM®) builds on technologies that have been developed and refined on previous Honda vehicles. With its 60-degree V-angle, the Odyssey's V-6 engine is inherently very smooth and has compact overall dimensions that allow for efficient packaging within the vehicle.

Compared to the 2010 model, the 2011 Odyssey engine gains VCM on the Odyssey LX and EX models, and all models gain refinements to increase power (such as a two-stage intake manifold), and to reduce internal friction (engine block honing and lightweight oil). The 2011 Odyssey engine develops four additional horsepower and five additional lb-ft. of torque (10 additional lb-ft. of torque relative to the previous-generation Odyssey LX and EX).

Powertrain Highlights

  • 3.5-liter i-VTEC V-6 engine with VCM
  • 248-horsepower @ 5700 RPM, 250 lb-ft. of torque at 4800 RPM
  • Available 6-speed automatic transmission
  • EPA City/highway fuel economy of up to19/28 miles per gallon (Odyssey Touring)
  • Emissions: ULEV-2 (CARB) / Tier 2, Bin 5 (Federal)

New Features

  • 6-speed automatic transmission (available)
  • 2-stage intake manifold
  • Cold air intake system

Engine Architecture

The engine is an advanced 3.5-liter, SOHC, 24-valve, 60-degree, V-6, aluminum-block-and-head design that is compact, lightweight and powerful. The i-VTEC valvetrain and high-efficiency intake manifold optimize cylinder-filling efficiency across a wide range of engine speeds. Low-restriction intake and exhaust systems, a 10.5:1 compression ratio and roller-type rocker arms further aid efficiency and power delivery across a broad RPM range.

The Odyssey's 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. The block is heat-treated for greater strength. The bearing caps are sintered. A forged-steel crankshaft is used for maximum strength, rigidity and durability with minimum weight. Instead of 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.

New for 2011, the piston skirt features a patterned coating process that improves oil retention to further reduce friction. Other friction-reduction measures include such important details as more elaborate, high-precision surfacing of the cylinder walls (plateau honing).

i-VTEC with Variable Cylinder Management (VCM)

To help improve the fuel efficiency of the engine, it incorporates the latest generation of Honda's Variable Cylinder Management (VCM). The Odyssey's VCM system can operate on three, four or all six cylinders, and is standard on all models.

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 efficiency increases. The VCM system combines maximum performance and maximum fuel efficiency - two characteristics that do not 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 virtually unnoticeable to the driver.

Dual-Stage Intake Manifold

The 2011 Odyssey engine's intake uses a dual-stage magnesium intake manifold that is designed to deliver excellent airflow to the cylinders across the full range of engine operating speeds. The induction system significantly boosts torque across the engine's full operating range. Internal passages and two butterfly valves within the intake manifold are operated by the powertrain control module to provide two distinct modes of operation by changing plenum volume and intake airflow routing.

At lower rpm these valves are closed to reduce the volume of the plenum and effectively increase the length of inlet passages for maximum resonance effect and to amplify pressure waves within each half of the intake manifold at lower rpm ranges. The amplified pressure waves significantly increase cylinder filling and torque production throughout the lower part of the engine's rpm band.

As the benefits of the resonance effect lessen with rising engine speed, the butterfly valves open at 4300 RPM to interconnect the two halves of the plenum, increasing its overall volume. An electric motor, commanded by the powertrain control module, controls the butterfly valves. The inertia of the mass of air rushing down each intake passage helps draw in more charge than each cylinder would normally ingest. The inertia effect greatly enhances cylinder filling and the torque produced by the engine at higher rpm.

High-Mounted Fresh Air Intake

The Odyssey has a high-mounted fresh air intake system that reduces air intake temperatures to help improve low-end torque.

Overrunning Alternator Decoupler (OAD)

The accessory belt that drives the alternator, power steering pump and A/C compressor uses a self-tensioning mechanism designed to dampen acceleration and deceleration loads. The Overrunning Alternator Decoupler (OAD) helps absorb dynamic variations in belt tension, contributing to a more stable operation. Nominal belt tension can thus be reduced by approximately 50 percent, helping reduce engine friction losses for improved fuel efficiency.

High-Flow Exhaust System

A low-restriction, high-flow exhaust system is crucial to efficient power and torque production. The Odyssey 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 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.

Linear air-fuel and oxygen sensors installed in each of the close-coupled catalytic converters make possible precise control of the air-fuel ratio. These sensors and the precisely controlled high-atomizing multi-hole fuel injectors help achieve almost complete combustion, for cleaner emissions. The result is compliance with the California Air Resource Board's ULEV standards as well as Federal Tier 2-Bin 5 emission requirements.

Active Control Engine Mount (ACM) and Active Noise Cancellation (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 Powertrain Control Module (PCM) to direct two ACM actuators - one positioned at the front and on at the rear of the engine - to move to cancel engine vibration. Inside the interior of the Odyssey, 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.)

Powertrain Control Unit (PCU)

The PCU contains two processors which communicate together to control the vehicle's powertrain. A 32-bit, 96MHz processor controls the Programmed Fuel Injection (PGM-FI) and the i-VTEC valvetrain, plus a 32-bit 80MHz processor which controls the transmission.

Programmed Fuel Injection (PGM-FI)

The PCU 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.

Drive-by-Wire™ (DBW) Throttle System

The 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 optimizes engine response to suit driving conditions. The system monitors throttle and brake pedal positions, throttle butterfly position, vehicle speed, engine speed and engine vacuum. This information is used to define the throttle control sensitivity.

Direct Ignition

The Powertrain Control Unit (PCU) monitors engine functions to determine the best spark timing. An engine-block mounted acoustic detonation/knock sensor "listens" to the engine, and based on this input, the PCU retards the ignition timing to prevent potentially damaging detonation. An ignition coil unit for each cylinder is positioned above each spark plug's access bore.

Regular Unleaded Fuel

To keep operating costs at a minimum, all Odyssey 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.

Maintenance Minder System and Tune-Up Intervals

The Odyssey's Maintenance Minder system calculates the engine's tune-up schedule based on driving conditions (tracked by the PCM). When determining proper maintenance intervals, the system minimizes owner guesswork about whether the vehicle is being operated in standard or severe conditions. The Odyssey'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, coolant and when to rotate the tires. A tune-up is not required until about 100,000 miles. (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 details.) Long-life fluids have been used for reduced maintenance costs and environmental impact (fluid disposal). As a result, engine coolant changes are needed about every 10 years or approximately 120,000 miles, and engine oil changes are required around 7,500 miles under normal driving conditions, or annually if fewer miles are driven per year. The maintenance minder system calculates the exact miles between service intervals.

Battery Management System (BMS)

The 2011 Odyssey has a Battery Management System (BMS) that is designed to increase the overall service life of the battery, reduce the chance of a dead battery and help deliver improved fuel economy. Should an Odyssey owner accidentally leave the headlights on or not close a door causing an interior light to remain on, after a set period of time the BMS will automatically terminate power delivery to prevent the battery from going dead. Moreover, the BMS continually monitors battery condition and will provide a warning message while automatically turning off the interior lights when battery condition or cranking capability drops too low. As a result of the discharge protection afforded by the BMS, the battery should always have enough reserve capacity left to start the engine.

The 3.5-liter V-6 engine in the Odyssey makes use of a powerful 130-amp alternator that charges in two different ranges - a low 12-volt range and a high 14-volt range. By closely controlling the alternator charge voltage, BMS works to keep the battery in a specific charge range which can extend the service life of the battery by more than 25 percent. With BMS keeping the battery in a specific charge range, the alternator can run more often in the low range which generates less drag on the engine resulting in improved fuel economy.

Should a battery or charging system issue occur, the information display on the Odyssey LX, EX and EX-L, or the Multi Information Display (MID) on the Odyssey Touring, will alert the driver with a text prompt such as, "BATTERY CHARGE LOW."

Five-Speed Automatic Transmission with Grade Logic Control

The five-speed automatic transmission on the Odyssey LX, EX and EX-L has several features engineered specifically to match its performance requirements, including extra-wide gear ratios for good low-end response and comfortable highway cruising; a computer-controlled lock-up torque converter; a rigid alloy case; and a four-shaft design. Honda Grade Logic Control technology is designed to hold the vehicle in a lower gear when climbing or descending a steep grade for improved performance.

The transmission features an expanded complement of smart logic controls. A computer-controlled lock-up torque converter is provided to maximize fuel economy. Torque-converter lock-up and shift timing are both managed by a CPU working in cooperation with the engine's central processing unit. An over-running clutch is provided for first gear to smooth upshift quality. A direct-control strategy is used to provide real-time pressure management of the transmission's clutches. Various control strategies are utilized to allow for smooth coordination of engine and transmission operations. For example, the driveline shock that often accompanies gear changes is minimized by momentarily reducing engine torque during shifting.

To reduce gear "hunting" and unnecessary shifting, Grade Logic Control is integrated into the shift programming of the transmission. Grade Logic Control alters the five-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 Odyssey 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.

Six-Speed Automatic Transmission with Grade Logic Control

To maximize driver control, acceleration and fuel economy, the Odyssey Touring models are equipped with a six-speed automatic transmission. Though comparable in size and weight to the existing five-speed automatic transmission, careful engineering of the layout and power flow minimizes size, parts count and overall weight.

The new six-speed automatic advances launch-feel, acceleration performance and fuel economy. Compared to the 5-speed transmissions, the new six-speed transmission has lower gear ratios (higher numerically) in first through fifth gears and in reverse. The lower gear ratios improve acceleration and pulling power. The sixth gear ratio is taller (lower numerically) than the top gear in the five-speed transmission. The taller final gear allows for a relaxed cruising rpm and enhanced highway fuel economy.

The six-speed automatic transmission also includes engineering enhancements aimed at improved performance and economy. 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 economy, 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.

Odyssey Gear Ratio Comparison Table

Gear 2011 6AT Ratio 2011 5AT Ratio 2010 5AT Ratio (i-VTEC)
1st 3.359 2.697 2.697
2nd 2.094 1.606 1.606
3rd 1.484 1.071 1.071
4th 1.065 0.765 0.765
5th 0.754 0.612 0.580
6th 0.555 -- --
Reverse 2.269 1.888 1.888
Final Drive 4.25 4.31 4.31

Multi-Clutch Lock-Up Torque Converter

The all-new six-speed automatic transmission teams with a brand new 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 new lock-up assembly not only reduces heat build-up during operation, but also features improved overall lubrication that generates better cooling. The new torque converter allows for lock-up activation during a much wider range of driving conditions for improved fuel economy.

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