Squint and you might see it.

    Audi has been spied testing a very normal-looking S6 sedan prototype on some wintery roads.

    The only giveaway that something is awry with this vehicle is the large apparatus at the the rear. It appears this bulky equipment is changing the location of the exhausts from the outside to more centrally-mounted units.

    The regular quad exhaust tips have been blanked out with patches and there are now only two centrally-mounted exhaust tips. This is very strange as Audi ‘S’ vehicles typically have quad exhaust tips.

    Our spy photographers noted the Audi S6 prototype was “very loud but didn’t look that different”.

    Everything else about this prototype seems to be extremely similar externally to the current model. We don’t get a look inside though.

    It’s unclear what Audi is testing out exactly with this vehicle but it clearly has something to do with the exhaust system.

    One particular option that Audi could be investigating is beefing up the outputs of the S6’s twin-turbo powertrain. This would answer why this prototype apparently made so much noise.

    In Australia, the current-generation Audi S6 is solely available with the 2.9-litre twin-turbo V6 engine with a 48V mild-hybrid that produces 331kW of power and 600Nm of torque. It’s mated to an eight-speed torque-converter automatic transmission.

    A version of this engine, sans the 48V mild-hybrid system, is also used in the Porsche Panamera, Cayenne and Macan.

    In European markets, there’s also a 3.0-litre twin-turbo V6 diesel available that produces 253kW and 700Nm and is mated to a seven-speed dual-clutch transmission.

    It’s unclear whether its a twin-turbo petrol or twin-turbo diesel engine in this particular S6 prototype.

    Another probable option Audi could be working on is reducing the emissions of the twin-turbo powertrain. This would make sense for why there are large boxy forms under where the exhausts usually are.

    Audi has previously said it’s going all-electric in all markets, except for China, by 2033. It’ll also launch its last new global model with internal combustions engines (ICE) in 2025.

    The European Union is also looking to ban petrol, diesel and hybrid new cars from 2035.

    The European Commission is proposing a 55 per cent cut for new car CO2 emissions by 2030, and a 100 per cent cut by 2035. Current targets only call for a 35 per cent reduction by 2030.

    Even with the assistance of the 48V mild-hybrid system, the Australian-spec Audi S6 has a claimed fuel economy figure of 8.4L/100km.

    Audi locally launched the current, fifth-generation S6 in January 2020 and it hasn’t received a mid-life update yet.

    In February 2022, the S6 received a price increase of $5000 due to “rising material costs and continued supply challenges”. It now starts at $158,000 before on-road costs.

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    MORE: Everything Audi S6

    Jack Quick

    Jack Quick is an automotive journalist based in Melbourne. Jack studied journalism and photography at Deakin University in Burwood, and previously represented the university in dance nationally. In his spare time, he loves to pump Charli XCX and play a bit of Grand Theft Auto. He’s also the proud owner of a blue, manual 2020 Suzuki Jimny.

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