Powerwise, the A6 features a twin-turbo 4.2l V8 built by British engine wizards Cosworth, which was a subsidiary of Audi AG until 2004. It had an output of 331kW and 560Nm and a torque-converter transmission with shorter shifting times. Five driving modes enabled acceleration to 100km/h in 4.7 seconds and 250km/h. Equipped with the then newly developed Dynamic Ride Control (DRC) suspension, the A6 was sure to impress with its ideal spread between comfort and sportiness.
All first-generation RS 6 vehicles (C5) were handmade and to date, the C5 is the only RS 6 that is also a racing car from the start. The RS 6 Competition, with 349kW and a manual transmission, competed in the 2003 Speed GT World Challenge. At the end of its life cycle, quattro GmbH added a shot of additional power, resulting in 353kW and 560Nm.
In 2008, the second-generation C6 followed, wielding a twin-turbo 5.0l V10 engine. Power shot up to 427kW and 650Nm, while a six-speed automatic was used. The sedan needed 4.5 seconds to reach 100km/h; the Avant took 4.6 seconds. The first ceramic brake discs were made optional in the RS 6 and for its finale, the RS 6 plus Sport and a RS 6 plus Audi Exclusive were introduced. In all, 500 limited vehicles rolled out of the plant in Neckarsulm.
Fewer cylinders? That can’t be right. That is one critique that not only customers raised when Audi moved away from the 10-cylinder biturbo in 2013 and returned to a twin-turbo eight-potter with a smaller 4.0l of displacement — the smallest engine in the history of the RS 6. Additionally, the sedan was discontinued to make way for the Audi RS 7 Sportback.