Audi A6
Audi made a high-performance, 4.2-litre V8 engine (parts code prefix: 077, identification code: AEC) with a Bosch KE-Motronic ECU available as an option in the original European S4s, and made the decision to continue to do so with the S6, making a version of the 4.2 available as an optional upgrade over the 2.2-litre inline five-cylinder turbo. Unlike the five-cylinder turbocharged version, the V8-powered S6 was supplied with a four-speed automatic transmission as standard, but kept the quattro four wheel drive. A six-speed manual gearbox was also available as an option.
Audi 80
In Europe, the 90 designation for five-cylinder models was dropped for this generation, and all saloons were badged as 80, regardless of which engine they had. Audi of America went the opposite direction, and began selling the saloon as the 90. B4s for the American market typically offered more luxury and style even in the standard version, such as automatic transmission, cruise control, air conditioning and leather seats, all of which were usually optional at additional cost (or standard) on European models.