Mysterious Audi S6 Mule Spied With Loud (And Ugly) Exhausts

A weird Audi S6 mule was spotted by our spy photographers with a different kind of exhaust pipes and additional equipment mounted under the rear bumper. The prototype was described as “very loud”, coming with a combustion engine.

The dual exhaust pipes are placed lower and closer to the center than the decorative chrome elements borrowed from a lesser A6 S-Line trim. The current S6 is distinguished by the quad exhaust pipes. Those are functional in the US-spec model with the twin-turbo 2.9-liter TSFI V6 engine producing 444 hp (331 kW / 450 PS), but completely fake in the EU-spec S6 which comes with a mild-hybrid 3.0-liter V6 TDI engine producing 344 hp (257 kW / 349 PS).

The yellow indicators on the LED headlights suggest that this is a US-spec Audi S6, although as is the case with mules we can never be sure what lies under the bonnet. We already know that Audi is working on a facelifted A6 that is set to be unveiled this year, but the pictured S6 doesn’t necessarily have to be related to the updated model.

Our take is that Audi is using this mule to test a new engine. The company will stop ICE development in 2026 when it is expected to launch its last model with a combustion engine. Still, there are a few ICE-powered Audis on the way – including the upcoming Q5 and A4 – that will need cleaner engines in order to comply with the strict emission regulations.

Using the S6 body as a vessel for the development of new or improved versions of existing powertrains is a logical thing to do. After all, the A6 is based on the MLB architecture that is also underpinning several other models in Audi’s lineup and will likely soldier on until the carmaker becomes an all-electric brand by the early 2030s.