If you're familiar with the 2011 Chevrolet Volt, you probably know that it carries an onboard 1.4-liter four-cylinder engine that acts as a generator, powering the electric motors that drive the wheels (under most circumstances, anyway). Today at the Geneva Motor Show, Lotus unveiled a new take on the range extender engine, adding supercharging to improve efficiency.
The new Lotus Range Extender is a production unit for use in real cars. It uses a 1.3-liter three-cylinder engine with the added power of a supercharger to create 50 kilowatts of peak electrical power (67 horsepower) at just 3,500 rpm. The combination of small displacement plus the supercharger means it's more fuel efficient than most standard engines.
A naturally-aspirated (non-supercharged) version of the Range Extender was also unveiled, capable of producing 47 horsepower from 1,500 rpm to 3,500 rpm. The engines weigh just 112 pounds without the supercharger or 128 pounds with it.
Though the new Range Extender engine hasn't yet been placed in any production cars, it is on display in Geneva in Lotus' own Evora 414Evolution. Lotus hopes to contract the sale of the engine out to other carmakers for use in series-hybrid designs similar to those found in the Chevy Volt and Fisker Karma.