The all-electric Audi e-tron concept car was unveiled at the 2009 Frankfurt Motor Show, followed by 2009 LA Auto Show (in orange body colour), and at the 2010 24 Hours of Le Mans.
The Audi e-tron is a version of the R8 Coupe with a slightly smaller body utilising four electric motors rated at 317 PS (233 kW; 313 bhp) and 450 N m (332 lbf ft) of torque. However the proposed torque rating is the torque measured at the wheels, not at the output shaft — as is the industry standard, the true torque rating is around 678 N m (500 lbf ft). Other features include a 42.4 kWh liquid cooled lithium-ion battery pack, a need-based energy management system, LED technology used for all lighting units, independent cooling system for each axle; doors, covers, sidewalls and roof in carbon fibre-reinforced plastic; 3-mode flush gear selector (forward, reverse and neutral), instrument cluster with fold-out central display with integrated Audi MMI functions, climate control unit located to the right above the steering wheel, racing-inspired lightweight bucket seats, snow white and cognac interior colours, heat pump, climate control system; triangular double wishbones at the front axle and trapezoidal wishbones made of forged aluminum components at the rear axle, direct rack-and-pinion steering with speed-sensitive electromechanical steering boost, 235/35R19 front and 295/30R19 rear tires with a new blade design and the prototype version of an information processing system (car-to-x communication).
Claimed performance figures for the R8 e-tron is a 0–62 mph (0–100 km/h) acceleration time of 4.8 seconds and a limited top speed of 124 mph (200 km/h). The car has a limited all-electric range of 154 mi (248 km). A full charge at 230 volts takes six to eight hours, while a 400-volt quick charger would knock the charge time down to about two and a half hours. Braking is accomplished and energy is recaptured through the electric motors’ regenerative function, unless the car detects more aggressive deceleration is required, at that point a conventional electromechanical system featuring carbon-ceramic discs starts functioning to assist. The battery pack and its necessary inverter and power accoutrements weigh about 1,040 lb (472 kg), or nearly a third of the E-Tron’s approximately 3,500 lb (1,588 kg) curb weight achieved by the excessive use of carbon fibre, magnesium and aluminium. The car has a weight distribution of 42% at the front and 58% at the rear.