Within the year, Toyota says it will market a passenger vehicle using a gasoline engine, electric motor, and electric generator to achieve nearly twice the fuel efficiency of conventional gasoline cars, as well as reduced emissions. How the power sources engage depends on driving conditions. An improved-efficiency gasoline engine (Atkinson cycle) provides the main power to drive the wheels, but drive power can also be supplied by an electric motor feeding from the nickel-metal-hydride battery and an electric generator. Efficiency is also boosted by automatically cutting the engine when the vehicle is stopped and regenerating energy during deceleration. The transmission is designed as an electronically controlled, continuously variable system that can fluidly adjust the rpm of the engine, generator, and motor to accommodate acceleration and deceleration.