Honda Motor Co. has a new and greatly improved one-motor hybrid system for small cars. But engineers for the next Civic are leaning toward the more powerful and fuel-efficient two-motor system that debuted in the mid-sized Accord Hybrid that went on sale last fall.
Honda has not said what kind of gasoline-electric drivetrain the next-generation Civic Hybrid, expected around 2016, will get. But Hiromitsu Ishibashi, chief engineer for the one-motor system at Honda R&D Co., said engineers are considering the two-motor layout.
Honda has doubts about how the one-motor system's dual-clutch transmission will be accepted in America, Ishibashi said on the sidelines of Automotive World, an annual technical conference here. And the two-motor system would deliver better fuel economy.
The newly developed one-motor system, deployed in the Fit hatchback and the Fit-based Vezel subcompact crossover, pairs a 1.5-liter engine with an electric motor with a dual-clutch transmission.
Hybrid versions of both cars already are on sale in Japan, but there are no current plans to bring the gasoline-electric versions to the United States.
The two-motor Accord Hybrid uses a continuously variable transmission.
'Customers don't care'
"U.S. customers don't care that much about which system [they get], as long as fuel economy and drivability are good," Ishibashi said. "Also, DCTs have not been that well received."
Honda's two-motor system is capable of delivering better fuel economy than the one-motor system because it allows for longer electric-only driving. The Accord Hybrid has a 50-mpg city rating, better than any other mid-sized sedan. The downside: added cost.
Ishibashi said engineers are still evaluating which system would work best in the Civic but added: "My personal guess is it could be two motors."
Honda said in November it will replace step-geared automatic transmissions with CVTs in all automatic Civics starting with this year's freshening of the nameplate.
The company has not officially said when a re-engineered hybrid will arrive. The current version uses Honda's Integrated Motor Assist system, a one-motor technology often criticized for falling short in fuel economy and power. It achieves a combined city-highway 44 mpg rating.
Honda has been wrestling with what powertrain to use in the Civic Hybrid, partly to make it a tougher competitor of the Toyota Prius, which gets a combined city-highway 50 mpg rating.
Honda engineers have said in the past that one option might be two types of two-motor systems: a more expensive one for the Accord and a lower-cost version for the Civic.
Even if Honda goes with a one-motor system, it would still bring gains.
The new one-motor system, dubbed Sport Hybrid Intelligent Dual-Clutch Drive, delivers across-the-board improvements over the outgoing system.
For the redesigned Fit Hybrid that debuted last year in Japan, Honda switched to a lithium ion battery, from a nickel-metal hydride one, boosting energy capacity 50 percent. Power output was more than doubled to 22 kilowatts, from 10. Engineers also made the battery 23 percent smaller and more than doubled the torque to 118 pounds-feet, from 58.
Honda also slashed the weight of the intelligent power unit, which includes the battery, inverter, DC/DC converter and battery control unit, by 40 percent.
The Fit Hybrid also gets a new Atkinson's cycle 1.5-liter engine.