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 Quattro
At the Paris Motor Show in 2010, Audi presented the quattro concept on the occasion of the 30th anniversary of the original Audi Quattro and the Audi quattro four-wheel-drive system. Based on the RS5, it features a modified 2.5 L five-cylinder TFSI engine shared with the TT and a 6-speed manual transmission from the S4. The engine was claimed to generate a maximum power output of and of torque. The revolutionary design features depicted on the concept car would eventually make their way on future Audi models.