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 A6
There are now six petrol and four diesel engines available for the upgraded A6. All petrol engines now feature cylinder-direct Fuel Stratified Injection (FSI) technology, and all diesel engines now feature common rail (CR) and Turbocharged Direct Injection (TDI) technologies. There is a new petrol engine, a 3.0-litre supercharged V6, badged as 3.0 TFSI or 3.0T. This new engine is shared with the 2010 Audi S4 and S5 Cabriolet, although in the latter two applications in a higher state of tune and mated to a 7-speed S-tronic dual-clutch transmission.