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
The Audi image at this time was a conservative one, and so, a proposal from chassis engineer Jörg Bensinger was accepted to develop the four-wheel drive technology in Volkswagen's Iltis military vehicle for an Audi performance car and rally racing car. The performance car, introduced in 1980, was named the "Audi Quattro", a turbocharged coupé which was also the first German large-scale production vehicle to feature permanent all-wheel drive through a centre differential. Commonly referred to as the "Ur-Quattro" (the "Ur-" prefix is a German augmentative used, in this case, to mean "original" and is also applied to the first generation of Audi's S4 and S6 Sport Saloons, as in "UrS4" and "UrS6"), few of these vehicles were produced (all hand-built by a single team), but the model was a great success in rallying. Prominent wins proved the viability of all-wheel drive racecars, and the Audi name became associated with advances in automotive technology.