engine and related components under the aluminium bonnet of the RS6. Drive output passes through a ZF 6HP28A six-speed tiptronic automatic transmission. The gear ratios are: 1st: 4.171, 2nd: 2.340, 3rd: 1.521, 4th: 1.143, 5th: 0.867, 6th: 0.691, with shortened shift times, with "Dynamic Shift Programme" (DSP) and "Sport" mode. It has paddle-shifts mounted behind the flat-bottomed steering wheel, similar in design to the Audi B7 RS 4. The gearbox is set by default, in conventional automatic mode, to delay up-changes during acceleration, and change down earlier to maximise engine braking. Downshifts in all modes of operation include the Powertrain Control Module electronic control unit (ECU) "blipping" the Bosch "E-Gas" drive by wire throttle, for smoother shift shifts. The hydraulic torque converter includes a lock-up function in all forward gears and is able to completely disconnect when the vehicle is stationary, thus saving fuel. Like all Audi "RS" models, the RS 6 is fitted with Audi's 'trademark' Quattro permanent four-wheel drive as standard. This version of the RS 6 uses the latest asymmetric dynamic 40:60 front-to-rear default torque distribution from the Torsen T-3 'automatic torque biasing' (ATB) centre differential. This latest incarnation of the Torsen Quattro, first seen in the B7 RS 4, can automatically dynamically apportion up to a maximum 100% torque to the rear axle, or up to 80% to the front, dependent on traction conditions. The front and rear final drives are conventional "open" differentials (ratio 3.317) and use the Audi "Electronic Differential Lock" (EDL). EDL is a part, or "function", of the Bosch ESP 8.0 Electronic Stability Programme, which also includes "Anti-Slip Regulation" (ASR) traction control system. EDL does not 'lock' the differential in a traditional sense, but uses electronics to compare the speeds of the two wheels on an axle, and brakes any wheel that is sensed to have lost traction (by rotating faster than the opposite wheel, beyond normally accepted deviations). This braking of a slipping wheel has the effect of transferring torque across the axle to the other wheel, which is assumed still to have traction. C6 steering and suspension Like the previous RS6 and the B7 RS 4, this generation of RS 6 includes Audi's "Dynamic Ride Control" (DRC) Sports suspension system. The system is mainly mechanical, using a pump to provide additional pressure in the diagonally linked dampers (shock absorber) during cornering, to counteract rolling and pitching. The system can dynamically