Honda Automobiles: 2012 Honda CR-V Powertrain Delivers Both Performance and Efficiency

The all-new 2012 CR-V features a sophisticated powertrain that offers a refined balance of versatile performance for city and highway driving, high levels of fuel economy for an SUV, and confidence-inspiring capability in low-traction conditions.

Improvements to the 2012 CR-V’s 185-horsepower, 2.4-liter, i-VTEC DOHC 4-cylinder engine contribute to more power (+5 horsepower) and enhanced torque delivery compared to the previous generation. Up by over 10 percent in highway driving, the EPA-estimated city/highway fuel economy rating1 increases in front-wheel-drive models to 23/31 mpg (+2/+3 mpg) and models equipped with the available Real Time AWD™ system improve to 22/30 mpg (+1/+3 mpg). Plus, an ECON operating mode increases the potential for drivers to improve the vehicle’s fuel efficiency when the system is activated. The CR-V comes standard with a 5-speed automatic transmission, and given the increase in horsepower, now has slightly higher overall gearing (lower numerically) to aid fuel economy.

New Powertrain Technology

  • Enhanced engine design with improved horsepower and torque
  • Available Real Time AWD with Intelligent Control System™

Powertrain Summary

  • 2.4-liter DOHC i-VTEC 4-cylinder engine with185 horsepower @ 7000 rpm (+5 horsepower) and 163 lb-ft. of torque @ 4400 rpm (+ 2 lb-ft.)
  • Standard 5-speed automatic transmission
  • Available Real Time AWD with Intelligent Control System™
  • Estimated EPA fuel economy of 23/31 city/highway (FWD) and 22/30 (AWD)
  • CARB Ultra Low Emission Vehicle-2 rating and Federal Tier 2/Bin 5 rating

The CR-V’s transmission works in conjunction with the engine’s Drive-By-Wire™ throttle control to smoothly shift between gears. Additionally, Honda’s unique Grade Logic Control system can intuitively hold the most appropriate gear on hilly roads, reducing unnecessary shifting. For drivers who desire the four-season confidence of all-wheel drive, the new Real Time AWD with Intelligent Control System debuts on the 2012 CR-V and is available to help provide traction in low-grip driving conditions such as snow, rain and unpaved road surfaces.

The electronically controlled all-wheel-drive system replaces the previous-generation CR-V’s Real Time 4WD™, a hydraulically activated “dual-pump” system. Compared to the prior system, the electronically activated system offers a faster, more intuitive initial response when a loss of traction is detected. It also reduces weight by 17 percent and minimizes internal friction by 60 percent. The advancements help to further minimize the negative impact on fuel economy inherent to virtually all four-wheel-drive systems.

185-horsepwoer 2.4-liter DOHC i-VTEC 4-Cylinder Engine
The 2012 CR-V is powered by a dual overhead cam (DOHC), all-aluminum, 2.4-liter inline four-cylinder design that features 16 valves and a high-volume intake manifold. The K24Z7 engine produces 185 horsepower at 7000 rpm and torque is rated 163 lb-ft. at 4400 rpm – up by 5 horsepower and 2 lb-ft. of torque compared to the previous generation. Despite its added power, the engine also delivers superior EPA-estimated fuel economy compared to its predecessor, up by over 10 percent on the highway compared to the 2011 model, in both front-drive and all-wheel-drive versions.

A host of innovative features are designed to deliver a cutting-edge combination of performance, fuel efficiency, and low emissions. Most apparent is the i-VTEC “intelligent” valve-control system, a technology that combines VTC (Variable Timing Control) – which continuously adjusts camshaft phase – with Variable Valve Timing and Lift Electronic Control (VTEC) – which changes valve lift, timing, and duration. The combination of these two systems results in impressive horsepower and torque – with good fuel economy and low exhaust emissions.

In keeping with Honda’s proven commitment to the environment, the CR-V engine meets strict California Air Resource Board (CARB) Ultra Low Emission Vehicle-2 tailpipe emissions standards and Federal Tier 2-Bin 5 emission standards.

Engine Block/Crankshaft and Low-Friction Engine Design
The 2.4-liter engine uses a two-piece, die-cast aluminum block and bearing cap design that helps maximize strength and rigidity while minimizing noise and vibration. The compact upper element features cast-in iron cylinder liners for outstanding durability and the lower element consists of a single-casting crankshaft carrier fitted with ferrous-carbon bearing-cap inserts that add to its overall structural rigidity. Each journal on the forged-steel crankshaft is micropolished to help reduce internal friction and improve durability.

The CR-V’s 4-cylinder engine makes use of new friction-reducing technologies designed to improve engine efficiency. The outer skirts of lightweight aluminum pistons now feature a low-friction coating applied in a unique dot-pattern application. The result is reduced overall friction as the pistons move within the cylinder bores. New low-tension piston rings also reduce friction. Plateau honing further lowers the friction level between the pistons and the cylinders by creating an ultra-smooth surface. Plateau honing is a 2-stage machining process that uses two grinding processes instead of the more conventional single honing process. This also enhances the long-term wear characteristics of the engine. Low viscosity oil (0W-20) is also used to reduce friction.

To improve smoothness throughout the rpm range and help lower noise levels, the CR-V is fitted with an internal balancer unit. Consisting of a pair of chain-driven counter-rotating shafts located in the oil pan, the balancing system helps quell the inherent second-order harmonic vibrations that normally impact in-line 4-cylinder engines.

Aluminum Cylinder Head
The i-VTEC engine uses a compact, lightweight cylinder head made of pressure-cast aluminum alloy. Its 4-valve-per-cylinder design has double overhead camshafts driven by a silent-type chain to ensure extremely precise control of the cam phasing. The cam drive is maintenance-free throughout the life of the engine. Each combustion chamber is designed with a relatively large “squish” area that promotes faster flame propagation on the power stroke. This results in more complete burning of the air-fuel mix and subsequently, low emissions.

i-VTEC Valvetrain
The CR-V uses an advanced valve-control system to combine high power output with high fuel efficiency and low emissions. This “intelligent” version of the 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. The pairing of VTEC and VTC results in excellent drivability, including more horsepower and torque at lower rpm levels, along with enhanced fuel economy and significantly lower emissions.

The i-VTEC system on the 2.4-liter DOHC engine employs two rocker arms with friction-reducing roller followers for each pair of intake valves, along with an intake cam that has separate lobes configured to optimize both low- and high-speed operation. Depending on engine load and rpm, an electronic controller determines which cam profile will be used and exactly how each intake will operate.

At low revs, where low lift and shorter duration provide optimal operation, the timing of the two intake valves is staggered and the lift asymmetrically skewed in favor of the primary valve. This helps to create a swirl effect within the combustion chamber that increases the efficiency of the burn process. At higher rpm, a hydraulically actuated spool valve causes a locking pin to engage the secondary rocker arm with the primary one, transitioning the secondary valve into a high-lift/long-duration mode that improves output above 5000 rpm on the CR-V.

VTC allows the timing of the intake camshaft to be continuously varied throughout the engine’s entire rpm range. Along with to helping boost power, VTC also provides a more stable idle (allowing idle speed to be reduced) and reduced pumping losses by effectively creating an internal EGR effect at low and mid engine speeds. The result is increased fuel economy and lowered NOx emissions. Operation of the VTC is electronically controlled and is determined by input from sensors that monitor rpm, timing, throttle opening, cam position and exhaust gases. Depending on conditions, VTC can vary the phasing of the intake cam (change its position relative to the crankshaft) by +/- 25 degrees. VTC activation is accomplished hydraulically via a spool valve that sends high-pressure oil to passages in the cam’s drive sprocket.

At idle, the timing is almost fully retarded to minimize valve overlap. In normal highway driving, the intake camshaft timing is advanced to provide overlap for EGR effect. With the throttle wide open, valve timing starts in an advanced condition at lower RPM and gradually changes to a delayed condition when redline is approached. This allows optimum cylinder scavenging and pumping efficiency and provides outstanding power and torque throughout the rpm range.

Programmed Fuel Injection (PGM-FI)
The CR-V’s Programmed Fuel Injections (PGM-FI) is a sequential multi-port fuel injection system that continually adjusts the precision of 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. The CR-V engine’s fuel injector nozzles create extremely small fuel droplets, which improves atomization and flame propagation inside the combustion chambers. The better atomization enhances combustion and reduces emissions.

Regular Unleaded Fuel Operation
To keep operating costs to a minimum, the CR-V is designed to use relatively less-expensive regular unleaded fuel, thanks to compact four-valve combustion chambers and precise fuel injection and spark control.

Drive-by-Wire Throttle Control
An electronic drive-by-wire system helps enhance the driving character of the CR-V from both a throttle pedal feel (good tip-in with direct response) and a transmission refinement perspective (less shift shock with short gear change intervals). With smart electronics connecting the throttle pedal to the throttle butterfly valve in the intake manifold, the engine response can be optimized to suit the driving conditions and to better match the driver’s expectations. By eliminating the direct throttle cable connection to the engine, the ratio between pedal movement and throttle butterfly movement can be continuously optimized.

The CR-V uses a DC motor to control the throttle butterfly position in the intake tract. To establish the current driving conditions, the system monitors pedal position, throttle position, vehicle speed, engine speed and engine vacuum. This information is then used to define the throttle control sensitivity.

The throttle system also works to enhance the 5-speed automatic transmission’s ability to make shifts faster and smoother. By coordinating the throttle opening with the transmission’s shifting functions, engine power can be precisely tailored to the needs of the transmission at every point during the shifting process. That means less shift shock and delay, no matter the driving situation.

All CR-V models are equipped with an ECON button on the left side of the instrument panel as part of the Eco Assist™ system. When activated, ECON mode alters the Drive-by-Wire throttle system response curve in the range from about 10 percent of pedal movement to 80 percent. With less gain, the throttle opening in this range increases more gradually to reduce a potentially excessive peak input for better fuel efficiency. ECON mode also alters the operation of the cruise control system and the air conditioning system, allowing for slightly increased variances with the set speed or the set temperature in order to conserve fuel whenever possible.

High-Efficiency Catalytic Converters
Key contributors to the CR-V engine’s excellent emissions performance are its high-efficiency catalytic converters. The exhaust manifold is cast directly into the aluminum-alloy cylinder head to reduce weight and to position each primary catalytic converter as close as possible to the combustion chambers. A high-efficiency close-coupled converter mounts directly to the cylinder head’s exhaust port 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. A high-efficiency exhaust system and high-density catalytic converters help the CR-V engine meet stringent ULEV-2 emissions certifications in California and Federal Tier 2 Bin 5 certifications.

Maintenance Minder
The CR-V’s vehicle maintenance schedule is calculated by the Maintenance Minder system. The Maintenance Minder system automatically indicates when to have standard service performed based on actual driving conditions (tracked by the ECU) and minimizes the guesswork related to whether the vehicle is being used in standard or severe use conditions for maintenance interval purposes. The display indicates when to change the oil, air cleaner, transmission fluid, spark plugs or coolant, as well as when to rotate the tires. As calculated by the Maintenance Minder system, the CR-V has an engine tune-up interval of 100,000+/- miles or more. (See Interior section for more details on the Maintenance Minder display that appears on the i-MID.)

Multi-stage Alternator Control
To improve battery life and help reduce fuel consumption, the CR-V has a new multi-stage alternator control system. By closely monitoring the battery’s charge state, the system can adjust alternator output more precisely than the previous high/low mode system. This fine control reduces excessive charge or discharge and can help increase battery life by up to 30 percent. By inhibiting surplus power generation, the multistage alternator control along with other electrical system improvements contributes to an improvement in fuel economy in the range of 0.5 miles per gallon.

5-Speed Automatic Transmission
A 5-speed automatic transmission with Grade Logic Control is standard on all CR-V models. It’s a compact three-shaft transmission design that is engineered for smooth operation and fuel efficiency. The CR-V’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.

For 2012, the transmission incorporates a range of features that combine to help improve the CR-V’s EPA-estimated fuel economy. A new Automatic Transmission Fluid (ATF) warmer uses the heat of the engine coolant (which warms more quickly after a cold start-up) to help bring the ATF up to operating temperature faster. New lower viscosity ATF is also used. The response of the lock-up clutch has been improved, and the number of clutch discs has been reduced, thanks to a new high-friction material. Finally, the CR-V has revised gearing to reduce cruising rpm.

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 the automatic transmission. 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 CR-V 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.

Real Time AWD with Intelligent Control System
New for 2012, the CR-V offers Real Time AWD with Intelligent Control System™, which represents a major advancement to Honda’s original Real Time 4WD system used in previous-generation models. The more compact and efficient Real Time AWD introduces a high degree of four-wheel-drive sophistication in rain, snow, dirt roads and dry pavement. System operation is completely automatic and virtually transparent in smoothness. Unlike some four-wheel-drive systems that require the driver to select a drive mode based on the perceived need, Real Time AWD’s automatic operation means the system is always ready to transfer torque to the rear wheels, allowing the driver to focus more on driving when situations are demanding.

The capabilities of the system are prioritized to further support high fuel efficiency and all-around drivability on-road as well as off-road. Assisting the front wheels when it is beneficial, Real Time AWD instantly powers the rear wheels when starting from a stop, even on dry pavement, working in cooperation with Vehicle Stability Assist (VSA) and the new Motion-Adaptive Electric Power Steering (EPS). For comparison, the previous-generation Real Time 4WD was designed to allow the front wheels to slip a small degree before torque was transferred to the rear wheels and its primary benefit was at low speeds. Plus, it did not interact with VSA. The new Real Time AWD system can operate at all speeds when needed. When torque transfer to the rear wheels is not required such as when cruising, drive to the rear wheels is decoupled for reduced drag.

The Intelligent Control System function of Real Time AWD cooperates with the VSA and EPS to assist the driver in maintaining vehicle control. For efficiency, the electric motor activating the hydraulic pump is idled when not required, further reducing drag within the system and helping to reduce energy consumption. Compared to the previous model’s Real Time 4WD, the new Real Time AWD design weighs 17 percent less (approximately 36 pounds total system weight) and has 60 percent less rotational drag compared to the previous-generation’s Real Time 4WD system.

The CR-V’s all-wheel drive system’s major components consist of the conventional front-wheel-drive system, a compact transfer case that distributes torque to a propeller shaft running the length of the vehicle, the rear differential, a new electronically-controlled hydraulic pump, a multi-plate clutch, and left and right rear-wheel driveshafts.

The previous-generation Real Time 4WD system was mechanically actuated using a pair of hydraulic pumps (one driven by the front wheels and one driven by the rear wheels) along with a ball cam mechanism to operate the clutch that sent power to the rear wheels. If the front wheels began to turn faster than the rear wheels, as would be the case if they were spinning on snow or ice, the difference in pressure between the two pumps would cause the clutch to be engaged, sending power to the rear wheels. The ball cam mechanism was designed to help speed engagement. The system was designed to react to front wheelspin quickly and then send a portion of the vehicle’s power to the rear wheels.

The new Real Time AWD still uses a multi-plate clutch, similar to the clutches used in Honda automatic transmissions, to connect the propeller shaft to the rear differential. But in place of the twin hydraulic pumps and ball cam mechanism used previously, the system now uses an electric motor driving a single hydraulic pump, which operates the clutch. The electric motor is controlled by the Intelligent Control System, which means that the system can actively apportion power based on the conditions. The system doesn’t merely react to front wheelspin; it minimizes wheelspin before it happens by sending power to the rear wheels accordingly.

When starting on snow for example, the system sends power to the rear wheels right from the start, minimizing the potential for front wheelspin. The system can also detect when the CR-V is climbing a hill and send a greater amount of power to the rear wheels in cooperation with the newly added Hill Start Assist feature. Hill Start Assist maintains brake pressure briefly after the brake pedal is released, giving the driver time to accelerate and smoothly resume motion. The Intelligent Control System instantly assesses the road’s slope angle using a G-sensor and the level of grip as detected by VSA in case of wheel spin, allowing added initial apportioning of torque to the rear wheels for smooth starts.

In summary, Real Time AWD offers the optimal balance of confident capability and user friendliness in a lightweight and fuel-efficient design. The driver can simply step on the accelerator and let the system maximize use of available grip and climbing capability.

1 Based on 2012 EPA mileage estimates. 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.

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