GM 1.4-liter four-cylinder range extender

GM's series hybrid electric power train took Best Green Engine in the International Engine Awards. This power train, which appears in both the Opel Ampera and Chevy Volt, relies primarily on a 111-kilowatt electric motor to drive the front wheels. That motor gets electricity from a 16-kilowatt-hour battery pack. An onboard 1.4-liter gasoline engine works as an electrical generator when the power is depleted.