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 A4
The next A4, internally designated "Typ" 8E, debuted on 10 October 2000, now riding on the Volkswagen Group B6 (PL46) platform. The car's new styling was developed under Peter Schreyer between 1996–1998, inspired by the Bauhaus design language of the C5 (second-generation) Audi A6 introduced in 1997. The 1.6-litre base model powerplant remained unchanged, but most other petrol/gasoline engines received either displacement increases, or power upgrades. The 1.8-litre 20-valve Turbo was now available in two additional versions, with or , this one with a standard six-speed manual gearbox, while the naturally aspirated 1.6-litre inline-four engine and 2.8-litre V6 were replaced by 2.0-litre, and all-aluminium alloy 3.0-litre units, still with five valves per cylinder, the most powerful of which was capable of and of torque. The 1.9 Turbocharged Direct Injection (TDI) engine was upgraded to , with Pumpe Düse (Unit Injector) (PD) technology, and was now available with quattro permanent four-wheel drive, while the 2.5 V6 TDI high-end model was introduced with and standard quattro. This generation of quattro consisted of default of 50:50 front to rear dynamic torque distribution. A Bosch ESP 5.7 Electronic Stability Programme (ESP) system, with anti-lock braking system (ABS), brake assist, and electronic brakeforce distribution (EBD) were standard across the range.