Detroit auto show: Audi continues its electrification with another E-tron concept

Just a few months after the E-tron debuted at the 2009 Frankfurt motor show, Audi has revealed the next chapter in its electric-car concept series at the Detroit auto show.

The Detroit show E-tron previews Audi's vision for a pure compact electric sports car. The new concept sits on a wheelbase that is nearly 9 inches shorter than the R8 and weighs in at just 2,976 pounds, of which 880 pounds come from the lithium-ion battery pack.

Weight is kept in check with the body constructed from aluminum, which also delivers high structural rigidity. Bolt-on parts such as the doors, body panels and roof are made from carbon-fiber-reinforced composites.

Performance numbers are impressive for the rear-wheel-drive sports car. Two electric motors are mounted on the rear axle to produce 204 hp and a staggering 1,955 lb-ft of torque. Zero to 62 mph happens in 5.9 seconds, top speed is limited to 124 mph and range is about 155 miles per charge, according to Audi.

For optimal performance capabilities, Audi placed the battery pack behind the cabin and in front of the rear axle for a weight distribution of 40:60. Also aiding in performance is torque vectoring afforded by the motors that can selectively distribute power to the wheels based on road and driving conditions.

Charging the battery can be done from a household outlet and would take 11 hours for a fully depleted pack, but a high-current 400-volt supply would cut charge time to roughly two hours. However, the Detroit show car doesn't have to rely entirely on power outlets for juice. It can also convert kinetic energy under braking to electric.

Other trick features include an automatic light-assist system that uses a camera to adjust beam settings based on traffic and weather conditions. For example, in fog, the headlights will adjust to provide a wider, more horizontal beam to cut down on glare.

Inside, the infotainment system is controlled with a touch-sensitive pad mounted on the steering wheel. Additionally, smart phones can be linked up to the car via a mobile network to preprogram information into the car's navigation system, address database and video player when you're not near the vehicle. Security updates and charge status can also be transmitted to your mobile phone.