In 2012 over 43% of all Audis sold had quattro four wheel drive.
The first was simply the Audi quattro and it was shown at the Geneva Motor Show in 1980. Modern Audis use one of three systems.
Those with transversely mounted engines, such as the TT, Q3 and forthcoming S3 and A3, use a multi-plate clutch Haldex system. Those with longitudinally mounted engines - the A4, A5, A6, A7, A8 and Q7 use a self-locking centre differential. A crown gear differential is used in the RS4 Avant and RS5 models, and will also be used in the RS6 Avant and RS7.
Quattro was first developed in the winter of 1976-1977 when Audi engineers were testing their powerful, front wheel drive, Audi prototypes in snowy Sweden. The Audis were being outperformed by a 70bhp Volkswagen Iltis (a four wheel drive Jeep type vehicle). Famously, Dr Ferdinand Piech then went off with a team of engineers and developed the first quattro system, which became the 1980 Audi quattro.
Over the years quattro became a mainstream staple of the Audi model range, and went on to propel the manufacturer to World Rally success with the Sport quattro S1.
