The 2007 Audi S6 sedan is based on the A6 and uses a detuned version of the V-10 from the S8. In this application, the direct-injection V-10 will make approximately 420 hp, thirty less than in the S8, and ninety less than in the Lamborghini Gallardo, which also uses an iteration of this powerplant. Power is sufficient to send the S6 from 0-60 mph in 5.1 seconds, 0.2 seconds behind its bigger brother. A six-speed Tiptronic handles the shifting, and torque is sent to all four wheels, with a 40/60 torque split favoring the rear wheels. The S6 boasts the usual S touches: aluminum-look mirrors, nineteen-inch wheels, and subtle aerodynamic modifications. While the S6 has eighty fewer horsepower than the 500-hp BMW M5, the price will also be at least $10,000 less. Both S6 and the S8 sedans will arrive at dealers this fall.