Audi will produce 250 special edition S4 models as part of its 25 years of Quattro anniversary celebrations.

Audi will produce 250 special edition S4 models as part of its 25 years of Quattro anniversary celebrations.

Dubbed the "S4 25quattro", the special car receives a silver exterior with bold front and rear bumpers, and carbon fibre trim on the front and rear spoiler. The car will also be fitted with special 18-inch DTM wheels shod with performance tyres, and a specially-tuned exhaust providing a rumble to complement its menacing physical characteristics.

Its interior is distinguishable by the Quattro shift knob that identifies the car as being one of 250. Other notable interior features include carbon fibre trim and grey stitching on the seats, floor mat edges, and leather for the gearshift cover and park brake lever. "Quattro" is embossed on the Recaro seats, which have grey nappa leather inserts.

Audi first introduced Quattro in 1980, and the S4 25quattro features the latest version of this all-wheel drive system with the asymmetric distribution of power and torque. The Torsen differential used is a self-locking system that builds up its locking action under power, while allowing for differences in speed while braking and in the bends.

Power is supplied by the proven 4,2-litre V8 engine which produces 253 kW at 7 000 r/min and a peak torque figure of 410 N.m between 3 000 and 4 500 r/min. All cars are fitted with a six-speed manual gearbox as standard, and the model tears from zero to 100 km/h in just over five seconds.

Sadly, the special edition Audi S4 25quattro will only be sold in the US. It will be unveiled at an Audi exhibit in California this week, where it forms part of a stand that includes the RS6 Speed Challenge GT race car and an Imperator dating from 1929.