Audi S6
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 A8
The D2 series S8 featured an uprated, version of the 4.2-litre V8 with four valves per cylinder. From late 1999, Audi increased this to five valves per cylinder with power increased to and . From launch in 1996, European-market models came standard with a six-speed manual transmission. A sports-recalibrated version of the ZF "5HP24" five-speed tiptronic automatic, featuring "Dynamic Shift Programme" (DSP) was released a year later and was the only transmission available in most other markets.