Audi A1 e-tron: Rotary hybrid

Audi's new A1 might be chasing the Mini, but the e-tron version, should it make production, will be after the Chevy Volt's scalp.

Unlike the first e-tron, which featured four electric motors, one for each wheel, and the second e-tron concept, which had two, one for each rear wheel, the A1 e-tron features a petrol engine, albeit one whose sole purpose is to keep the car's battery pack topped up.

The A1 e-tron's electric motor takes pride of place at the front of the car. The electric motor drives the front wheels and is powered by a Lithium-ion battery pack underneath the rear seats. In an arrangement similar to the Chevy Volt, there's a petrol engine, dubbed a range extender, to keep the batteries topped up. Unlike the Volt, though, the petrol engine sits at the rear of car, below the boot floor.

Even more intriguingly, the A1 e-tron's range extender engine is a single rotor Wankel engine (pictured above). After a blaze of glory in the 1960's, only one auto maker, Mazda, has persisted with this type of engine. Today it can be found powering the RX-8 sports car.

Like Chevy's Volt, the A1 e-tron's electric motor is the only engine driving the wheels. After a full charge, it can power the A1 for up to 50 kilometres without help from the rotary petrol engine.

The range-extending rotary engine generates 15kW and with the 12L fuel tank full, the petrol engine can top up the batteries for 200km, giving a total range of 250km.

The electric motor generates up to 75kW of power, and can propel the A1 e-tron from zero to 100km/h in 10.2 seconds and a top speed of over 130km/h.

According to Audi, the A1's e-tron's fuel consumption will be rated at 1.9L/100km based on the current draft standard for range-extended hybrid electric vehicles.

The Lithium-ion battery pack weighs about 150kg and takes three hours to recharge. Despite housing two engines, a fuel tank and a battery pack, the A1 weighs a respectable 1190kg.

The electric motor drives the front wheels via a single speed transmission. That's why the gear lever has just three options: Drive, Reverse and Neutral.

Audi has been priming the public for its Polo/Yaris-sized luxury city car for a while now, rolling out tonnes of sketches, as well as street art (above). The Mini-chasing A1 will soon go on sale in Europe with a variety of conventional petrol and diesel engines.

The navigation screen and interface controls in the e-tron look the same as in the standard A1, suggesting the same cabin tech. However, the e-tron uses an electronic display for its instrument cluster.

The navigation system comes with a 60GB hard drive and has detailed 3D topographic maps. Of the 60GB of hard drive space, 20GB can be used to store music. The available Bose audio system uses a 10-channel 465-Watt amp powering 14 speakers, which should equal a lot of sound for a small space.