Geneva Preview: Audi A1 e-tron is extended-range EV with Wankel rotary generator

Posted on 1 March, 2010


Audi still hasn’t released any images of its new electric A1 e-tron concept, but it has revealed some details of the car. Unlike the two previous e-tron sports car concepts that were both pure battery electric models, this one is a range-extended EV. Like the Chevrolet Volt, the A1 e-tron uses a smaller battery pack that allows it to go up to 31 miles on a single charge with no emissions.

Once the battery is depleted, an internal combustion engine kicks in to drive a 15-kilowatt generator and keep the A1 going. However, unlike the Volt or Fisker Karma, the A1 is using a single-rotor Wankel engine to drive the generator. While Wankels are not renowned for their fuel efficiency (much the opposite in fact), in this application it could work well thanks to its high power density.

The range with the Wankel running is bumped up by another 124 miles to a total of 155. With only a 15kW generator available to sustain the battery, it will be interesting to see how much performance is degraded in that mode. Audi claims the A1 e-tron achieves 123.8 miles per gallon (U.S.) on the draft EU standard for ER-EVs. We should have more details tomorrow, so stay tuned.