Audi is working on a mid-cycle update for its A6 and included in the range will be a new hardcore RS 6 Avant variant, prototypes for which were recently spotted testing at the Nürburgring.

The hardcore RS 6 Avant is thought to adopt Audi’s GT designation, which would make it an RS 6 Avant GT. Audi has previously used the designation on the R8 supercar to mark the end of a model’s run.

The regular RS 6 Avant has been on sale in the U.S. since the 2021 model year, and the hardcore GT version can be distinguished by a new front fascia, revised rear diffuser, and enlarged rear wing.

Each element is similar to designs shown on Audi’s 2020 RS 6 GTO concept, which was built as a homage to the Audi 90 IMSA GTO race car of 1989.

With Audi already testing prototypes for an electric RS 6, the hardcore RS 6 Avant may be the last RS 6 launched with an internal-combustion engine. Audi has already committed to launching its final vehicle with an internal combustion engine in 2026.

As is the case with Audi’s R8 GT models, there isn’t likely to be any increase in power. Rather, performance gains in the GT models are made via less weight and improved aerodynamics. Some potential upgrades for the hardcore RS 6 Avant will include light alloy wheels, carbon ceramic brake rotors, and carbon fiber body parts.

Under the hood should be a twin-turbocharged 4.0-liter V-8 matching the 621 hp of the RS 6 Avant Performance launched last year. It’s possible some tweaks will be made to the RS 6 Avant’s 8-speed automatic and all-wheel-drive system for the new variant.

Look for the hardcore RS 6 Avant to debut in 2024, meaning it should arrive as a 2025 model. The electric RS 6 is thought to arrive around the same time.