Lotus Engineering has reached an agreement with the Spanish Fagor Ederlan Group to develop and produce a small engine for use as a range extender in electric vehicles – a system similar to that found in the Chevrolet Volt. Lotus first showed its 1.2-liter inline-three engine at the Geneva Motor Show in the Evora 414E and Proton Emas concepts.

Both cars used a similar series hybrid powertrain architecture, where an electric motor provides the drive torque while the engine only drives a generator to sustain the battery after the plug-in charge has been depleted.

Because this new engine is designed specifically for use as a range extender rather than a primary power source, Lotus has been able to optimize the efficiency and reduce the weight. An adapted off-the-shelf engine like the one in the Volt is still designed to hold accessories like the alternator, air-conditioning compressor and power steering pump. Lotus has left out these structures for a lower cost and mass.

Lotus and Fagor Ederlan will take the 47 horsepower engine to production and offer it up to any automaker that wants to build an extended range electric vehicle, but no production timing or customers have been announced yet.