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 RS 4
The B8 RS4 is using the Volkswagen MLB platform. It is also only available with the dual clutch S-tronic gearbox configuration, allowing the car to accelerate from in 4.7 seconds. Compared to the related B8 S4, the RS4 features larger bumper air dams and features a double exhaust tailpipes compared to the S4's double twin (quadruple) exhaust tailpipes.