(Detroit, January 11, 2010) Audi has introduced its second electric sports car concept in just five months at the North American International Auto Show. The Detroit showcar e-Tron is a smaller less powerful followup to the original e-Tron that debuted last September in Frankfurt.

The previous concept car was based on the platform of the current R8 supercar and featured all-wheel-drive with four electric motors. The new car is significantly smaller and virtually matches the dimensions of last year's Volkswagen BlueSport Roadster concept with a length of just 154.7 inches, more than a foot shorter.

The Detroit e-Tron again uses a lithium ion battery pack albeit a smaller 45 kilowatt-hour unit compared to 53 kWh in the earlier car. The new concept is 550 pounds lighter at 2,976 pounds. The battery pack is mounted between the cockpit and rear axle of the mid-engine coupe giving a 40/60 percent front/rear weight distribution.

The smaller size of the new car contributes to a smaller frontal area for significantly reduced aerodynamic drag. The air intakes in the grille and on the flanks also have thermostatically controlled slats that open only when required by cooling demands. When closed the air-flow through the bodywork is eliminated, also reducing drag.

The new concept dispenses with Audi's signature quattro all-wheel drive. The first e-Tron had four motors each, driving a wheel. This time only the rear wheels have drive motors. The combined output of the motors is 204 horsepower with 1,954 pound-feet of torque at the wheels. The massive torque numbers are the result of including the multiplication factor of the reduction gears.

Like many other Audis including the A8, R8 and TT, the concept is based on an aluminum space frame to help minimize the weight.

The Detroit concept is quick although not quite as fast as the first electric sports car. It is claimed to accelerate to 62 mph in 5.9 seconds while the all-wheel drive concept accomplished the same feat in 4.8 seconds.

The combination of the lower mass, reduced drag, and lower performance means the new concept retains the same 154 mile plug-in range as the first concept even with a smaller battery.