Audi S6
Audi made a high-performance, 4.2-litre V8 engine (parts code prefix: 077, identification code: AEC) with a Bosch KE-Motronic ECU available as an option in the original European S4s, and made the decision to continue to do so with the S6, making a version of the 4.2 available as an optional upgrade over the 2.2-litre inline five-cylinder turbo. Unlike the five-cylinder turbocharged version, the V8-powered S6 was supplied with a four-speed automatic transmission as standard, but kept the quattro four wheel drive. A six-speed manual gearbox was also available as an option.
Audi RS 6
It has an electronically controlled five-speed ZF 5HP24A tiptronic automatic transmission (parts code prefix: 01L, identification code: GAG) (gear ratios—1st: 3.571, 2nd: 2.200, 3rd: 1.505, 4th: 1.000, 5th: 0.804), with lock-up torque converter in all forward gears. It has "hill detection" capability, and, despite many press articles stating that the gearbox was programmed to "blip" the throttle for downshift gear changes, no UK owners have ever found this feature to be present. The transmission control unit ECU incorporates "fuzzy logic" with its "Dynamic Shift Programme" (DSP), with the shift pattern adapting to suit individual driving styles. 'Tiptronic' manual control can be achieved with either the floor-mounted gear shift lever, or the steering wheel mounted 'paddles'.