Audi Ur-S4 / Ur-S6
The Ur-S4 was produced from 1991 to 1994, while the Ur-S6 was produced from 1995 to 1997. They both featured a 2.2 litre, 5-cylinder engine with turbocharging and an intercooler, with of torque. In Europe, V8-powered versions of both S4 and S6 were available. The S4 version sported a engine (the same "ABH" engine as in Audi V8), the S6 had an upgraded engine "AEC" with . American versions featured a 5-speed manual transmission and in Europe a 6-speed, as well as a 4-speed automatic transmission could be substituted.
Audi A8
A sports-optimised ZF "6HP26-A61" six-speed tiptronic automatic transmission with "Dynamic Shift Programme" (DSP) and "sport" mode, with steering wheel mounted paddle-shifters, is the only offering. Output is transmitted via Audi's quattro generation IV all-wheel drive system, initially using the Torsen T-2 50:50 dynamic centre differential, and from 2007 for the 2008 model year, utilising the Torsen T-3 asymmetric dynamic centre differential, with a "default" torque distribution of 40 percent to the front axle and 60 percent to the rear. If the road conditions change, the purely mechanical differential responds without any delay; it can divert up to 85 percent of power to the rear wheels, and as much as 65 percent to the front wheels.