Audi revealed the details of the RS 6 Avant on December 5, 2012. Its twin-turbo 4.0 L (3,993 cc) TFSI V8 engine develops 412 kW (560 PS; 553 bhp) at 5700-6600 rpm and 700 N⋅m (516 lbf⋅ft) of torque at 1750-5500 rpm. This will enable the RS 6 Avant to accelerate from 0 to 100 km/h (62.1 mph) in 3.9 seconds. The top speed is limited to 250 km/h (155.3 mph) by default. By adding the optional Dynamic or Dynamic Plus package, this top speed is increased to respectively 280 km/h (174.0 mph) or 305 km/h (189.5 mph). Audi claims an average fuel consumption of 9.6 L/100 km (29.4 mpg‑imp; 24.5 mpg‑US) and CO2 emissions of 223 g/km. In order to accomplish this, Audi has added a start-stop system and a cylinder on demand system. The RS 6 Avant is offered with an 8-speed tiptronic transmission.

The C7 RS 6 was not offered in North America, however that market received RS 7 Sportback which shares the same powertrain and platform.