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Wednesday, November 30, 2011

Honda unveils next-generation engines

Honda Motor Co. today unveiled a lineup of four- and six-cylinder engines and a family of continuously variable transmissions that will reach the market over the next two years.
All four-cylinder engines in the so-called Earth Dreams family will have direct injection and double overhead cams. New and redesigned Honda and Acura models will carry the new powerplants. Some products now on the market could get the new engines before they're redesigned, said Keiji Ohtsu, a chief engineer with Honda R&D.
Some base versions of current models will keep their single-cam, four-cylinder configurations throughout their life cycle as a cost-saving measure. A new V-6 will remain single-cam but gain considerable power.
Honda Motor CEO Takanobu Ito pledged that the automaker wants to achieve a "zero carbon footprint" and have "the No. 1 fuel economy in each (vehicle) category within the next three years."
The specifications for the new Honda engines are:
• A 3.5-liter V-6 with 310 hp and 265 pounds-feet of torque. This is 30 more horsepower and 11 more pounds-feet than the outgoing 3.5-liter engine in the Acura TL.
• A 2.4-liter inline-four with 181 hp and 177 pounds-feet of torque. This will be the base engine in the redesigned Accord coming next fall, and could find its way into the midcycle change for the CR-V in 2013.
• A 1.8-liter inline-four with 148 hp and 133 pounds-feet of torque, which could be installed in the 2013 midcycle change for the Civic.
• A 1.5-liter inline-four with 127 hp and 111 pounds-feet of torque for the Fit, perhaps in time for the midcycle change in 2012.
• A 1.6-liter turbodiesel engine that has comparable power to a current 2.2-liter diesel, with 220 pounds-feet of torque, but much better fuel economy.
Ohtsu said the power figures were preliminary and likely understated. Compared with the current four-cylinder engines, the new design will carry at least a 10 percent fuel economy advantage.
New transmissions
In addition, Honda has designed three continuously variable transmissions, one for mid-sized cars such as the Accord, and two for smaller vehicles such as the Civic, Fit and minicars.
Honda is betting big on continuously variable transmission technology, and will use it as its base automatic transmission offering across all four-cylinder engines.
Although current CVTs have a "rubber band" feeling similar to a slipping clutch under acceleration, the Honda system has less feeling of slippage, said Hideki Wakamatsu, general manager of Honda r&d.
Also, the engine control software has been remapped so there is less hunting between the engine and CVT for optimal engine revs and transmission ratios during sudden acceleration, Wakamatsu said.
Honda will continue to offer manual transmissions for markets such as Europe that prefer stick shifts. And traditional stepped-gear automatics will be offered for vehicles such as sport sedans and sports cars where more immediate performance impact is needed, Wakamatsu said.
Hybrid advancements
As for hybrid advancements, Honda's upcoming Accord two-mode hybrid, when combined with a four-cylinder engine, will have equivalent power to the Camry Hybrid, but better fuel economy than the Camry's combined 41 mpg rating, said Yusuke Hasegawa, senior chief engineer with Honda r&d.
When combined with a V-6 engine, the hybrid system will create V-8 power and four-cylinder fuel economy. The system can run in EV-only mode, EV-and-gasoline for passing and acceleration, or gasoline-only for highway cruising.
The two-mode hybrid uses a twin-cam profile. But instead of using its VTEC profile for more power, the hybrid version shifts between the Atkinson cycle for leaner-burning of fuel, and the traditional Otto cycle when more power is needed, depending on the torque load on the engine, Hasegawa said.
In EV mode, the Honda plug-in hybrid can travel for as many as 15 miles at speeds up to 62 mph. The plug-in system has a switch that will allow the driver to save EV-mode ability until later in his drive, such as if he commutes from the empty suburbs to the crowded downtown.
Honda also showed an electric all-wheel hybrid drive system that sends power to the outside wheel during cornering, which aids in traction and performance.
When the new 3.5-liter V-6 is combined with a seven-speed dual-clutch transmission with an integrated hybrid-electric motor, the torque output between left- and right-side wheels is independently meted to the outside wheel, using the energy from regenerative braking to provide the power boost.

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