The range-extending 1.4-liter engine in the Opel Ampera and Chevrolet Volt won the “International Engine of the Year Award” for the best green engine in a field of 45 contenders, the first time in the 14-year history of the awards that a range-extending powertrain has won.

“Until the Volt and Ampera, the short range of battery electric vehicles has limited their suitability for everyday use,” said Uwe Winter, Opel vehicle line director and chief engineer, who accepted the prize from Engine Technology International magazine. “Our revolutionary propulsion system removes this obstacle by uniting the environmental friendliness of electric drive with the long range of a combustion engine. And the Best Green Engine Award is the highest recognition of this achievement.”

A panel of 76 motoring journalists from 35 countries judges 12 categories of excellence in powertrain engineering. There were 39 all-new engines in the contest.

A 16 kWh lithium ion battery powers the 111kW/150 hp electric motor of the Ampera/Volt. Depending on the style of driving and road conditions, distance of between 40 and 80 kilometers can be covered in the purely battery-operated mode, completely free of emissions. The wheels of the car are always powered electrically. In extended-range mode, which activates whenever the battery has reached its minimum state of charge, power is seamlessly inverted to the electric drive unit from a generator driven by the 1.4-liter, 63 kW/86 hp gasoline engine. Extended-range mode enables a total driving range of more than 500 kilometers without refueling.

The Ampera and Volt together have won numerous international awards including the “World Green Car of the Year 2011” and more recently the European “Car of the Year 2012.”