the Bosch Electronic Stability Programme (ESP) system, and works by monitoring and comparing the individual wheel speeds across an axle, and braking an individual wheel which is sensed to have lost traction (spinning), thus transferring torque across the axle to the wheel/tyre which does have grip. "Anti-Slip Regulation" (ASR), more commonly known as traction control system completes the Bosch ESP-related driver aids. C5 suspension and steering Utilising the same fully independent four-link front suspension, and double wishbone rear, as its related A6 and S6, the RS 6 was lowered by , with a 30% stiffer spring rate, and 40% increased compression damping. The RS6 also served as the debut model for Audi's "Dynamic Ride Control" (DRC) system. The DRC system is mainly mechanical, and uses a pump to provide additional pressure to individual dampers (shock absorbers) during cornering, acceleration or braking; to counteract rolling and pitching. The system can adjust the stiffness at each individual damper constantly; to maintain both a comfortable ride on straight roads, and a high level of poise and grip when cornering hard, accelerating, or braking. The DRC's main advantage is that it operates without the need for complicated electronics, as required in similar systems from Mercedes-Benz and other competitors. Its main drawback is that the DRC dampers have been known to fail (leaking fluid from the cross-linked circuits), which can affect the handling and ride quality of the vehicle; some owners have reported needing multiple replacements of faulty DRC units and many drivers have opted to replace the system with simpler and more reliable aftermarket coil-over suspension. C5 brakes, wheels and tyres The front brakes feature fixed Brembo 8-piston monoblock brake calipers, working with radially vented and cross-drilled brake discs, sized at in diameter, by thick. The rear features single-piston floating ATE calipers with integrated cable-operated parking brake mechanism, mated to radially vented disc and cross-drilled, sized by . Front and rear brake calipers are finished in a high-gloss black paint, with the fronts incorporating the Audi "RS" logo. Both front and rear discs are held in by metal pins to the lightweight disc hub, and allow of lateral thermal expansion from the hub centre. Bosch ESP 5.7 Electronic Stability Programme, with Anti-lock Braking System (ABS), Electronic Brakeforce Distribution (EBD), and Brake Assist (BA) was standard fitment. There were a total of three original equipment manufacturer (OEM) wheel and tyre types available with the RS