The Audi S6 4.0 TFSI quattro and its mechanical twin S7 were launched as a 2013 models, a year after the C7 Audi A6 and Audi A7 were released.

The Audi S6 and S7 are powered by a 4.0L DOHC twin-turbo V8 engine mated to a 7-speed S-tronic Double Clutch Gearbox. This engine makes 420 hp and 405 lb-ft of torque, plus there is a cylinder-deactivation system and a stop-start system for improved fuel economy. The 2013 Audi A8 shares the same engine, while the 2012 Audi S8 has a variant of the powerplant in a higher state of tune making 520 hp and 479 lb-ft of torque, both mated to an 8-speed automatic transmission.

The V8 performance option for the regular Audi A6, found in the 2004-11 Audi A6 4.2 FSI, has been discontinued and the S6 takes over as the engine upgrade.[5] The S6 now compares more closely with the BMW 550i[6] and Mercedes-Benz E550, which also use twin-turbo V8 engines and have available all-wheel drive (the 2013 BMW 550i xDrive starts at $65,595 USD while the 2013 Audi S6 has an MRSP of $72,795 USD).

UK sales began in May, with a starting price of £53,995 for the saloon, and £56,050 for the Avant.

0-30 mph = 1.2 seconds. 0-60 mph = 3.7 seconds. 0-100 mph = 9.2 seconds. 0-130 mph = 16.1 seconds. 1/4 mile = 12.1 @ 115 mph