The Audi 80 is a compact executive car produced by the German manufacturer Audi (initially known as Auto Union and Audi NSU Auto Union) from 1966 to 1996. It shared its platform with the Volkswagen Passat from 1973 to 1986 and was available as a sedan, and an Avant (Audi's name for a station wagon). The coupé and convertible models were not badged as members of the range but shared the same platform and many parts.
In North America and Australia, the 80 was sold as the Audi Fox for model years 1973–79, and as the Audi 4000 for model years 1980–87 in the USA. The Audi 90 was an upmarket version of the Audi 80. The original Audi Cabriolet was badged thus, without a number, but was closely related to the 80/90.
There were several different internal combustion engine types, of which the petrol engines included the fuel-injected "E" (Einspritzung), and carburetor "S", and the diesel engines included "D" (Diesel), "TD" (TurboDiesel), or "TDI" (Turbocharged Direct Injection).