Boasting a 4.2-liter V8 with 331 kW (444 hp / 450 PS) and 430 Nm (317 lb-ft) of torque, the RS5 rockets from 0-100 km/h in 4.6 seconds and tops out at an electronically limited 250 km/h (155 mph). If that isn't fast enough, Audi can remove the speed limiter to enable the car to hit 280 km/h (174 mph). Not bad considering the RS5 only consumes 10.8 liters of petrol per 100 km (21.78 US mpg).
To keep the beast under control, Audi installed a new crown-gear center differential. It 'can widely vary the distribution of torque between the front and rear axles. If necessary, up to 70 percent can flow to the front or as much as 85 percent toward the tail end.'
The RS5 will go on sale in Germany this spring, with a base price of approximately €77,700 ($103,870 USD). Unfortunately, Audi has been mum on U.S. availability but it doesn't look promising."