Kenworth Truck Company recently introduced a hybrid-electric truck, called the Kenworth T270 Class 6. In a press release, Mike Dozier, Kenworth chief engineer, said: "During steady driving conditions above 30 mph, the T270 hybrid operates like a standard diesel vehicle with all power coming from the engine. Below 30 mph, it uses a combination of diesel and electricity. The system automatically switches between the two modes of operation and is seamless to the driver." Kenworth will have limited production of medium duty hybrid trucks for municipal fleets and utility companies this year with full-scale production expected to follow in 2008. The goal for the T270 hybrid is to improve fuel economy by 30% in start-and-stop applications, such as utility trucks and pick-up and delivery. "The more stop-and-go in the application, the better the truck's performance," said Dozier.
The Kenworth hybrid uses braking events to generate and store electricity. The process is called regenerative braking. "That electrical power is then used for acceleration, assisting the diesel engine," said Dozier. "As a bonus, there's a reduction in brake wear since the generator produces braking energy."