August Horch founded the company in 1909 and produced the Audi Type A. August left Audi in 1920 but remained on the board of directors. In 1932 Audi merged with three other European Automakers to form Auto Union. They produced the Audi Front, the first European car to combine a six cylinder engine with front-wheel drive. The Audi logo, still used today, is four rings joined. Each ring represents one of the original companies that formed Auto Union.
Audi entered the United States in 1970 with the Audi 100. In 1974 the Audi 50 was produced. The Audi 50 was the first incarnation of the Golf/Polo concept, one that led to a hugely successful world car.
Audi, along with Volvo was the leader of the inline 5 cylinder, 2.1/2 2 L engine. This was a longer lasting alternative to the traditional 6 cylinder engines. In the 1980's Audi used this engine in their rally cars.
In the early 1990's, with the release of the Audi V8, Audi began to become a real competitor against luxury leaders Mercedes Benz and BMW. The most obvious bodyword difference was the new grille that was incorporated in the bonnet. By 1991, Audi had the 4 cylinder Audi 80, the 5 cylinder Audi 90 and Audi 100, the turbocharged Audi 200 and the Audi V8.
The 5 cylinder was dropped as a major engine but , a turbocharged 230 hp version remained. The Audi Coupé became the S2 and the Audi 100 became the S4. The S2 and S4 were the beginning of the mass-produced S series of performance cars.