Quattro GmbH is Audi’s tuning arm in the vein of BMW’s M or Mercedes-Benz AMG and from 2002 to 2004, they produced the C5 RS6 super sedan. Only the third RS branded model ever made, it was also the first one exported to North America. RennSport, or literally “Racing Sport”, is the meaning behind RS and represents Audi’s most potent high-performance level of cars featuring their latest advanced engineering and technology. Affectionately known in the Audi world as ‘R Cars’.
Featuring an all-aluminum 4.2-liter, twin-turbo V8 co-developed with Cosworth, the 2003 RS6 put out a heady 450 horses and 415 lb-ft of torque. The 11.6 psi of boost, twin air-to-air intercoolers and sodium filled exhaust valves were just some of the powertrain features used to make this beast fly. Only available with Audi’s signature Quattro AWD meant all that power had the benefit of four wheels with which to burn rubber.
Peak torque was on tap from 1950 rpm all the way up to 5700 rpm, which did its part in clocking a 4.4-second run to 60 mph during a 2003 Car and Driver comparison. Of course, handling was also turned up to 10 by lowering the RS6 by 0.8”, stiffening the springs 30% and increasing the damper compression by 40% versus a period S6 sedan.
On top of that, Audi’s Dynamic Ride Control debuted with the C5 RS6 and used a mechanical pumping system to provide variable suspension damping based on real-time conditions. All of this combined to have the ’03 RS6 win that four-way Car and Driver comparison and defeat the legendary E39 M5 from BMW.