There Was Almost A V12 Diesel-Powered Audi R8

In the year that is 2025, the idea of a supercar using anything but a petrol-powered engine is still a bit alien. Sure, a few hybrids like the Ferrari 296 GTS and McLaren Artura exist, but electric supercars don’t exist beyond the realms of ultra-expensive hypercars.

What else could power one? Well, there’s diesel – a fuel that is rapidly heading towards extinction in the European new car market and not one you’d associate with high performance. Efficiency? Yes. Excitement? Not really.

That could’ve been oh-so-different if the Audi R8 V12 TDI had made production. Yes, you read that right.

Revealed at the North American International Auto Show in 2008, it’s important to remember the context of diesel before we set off answering why on earth Audi even considered an oil-burning V12 supercar.

It was a time when diesel was being championed as the greener alternative to petrol, a time when Audi was dominating endurance racing with the R10 TDI which would take its third consecutive 24 Hours of Le Mans win later that year. And well, it was years before the Volkswagen Group dieselgate scandal would emerge.

Really, Audi was the king of diesel. Intended as a halo showcase of its TDI capabilities, the Audi R8 V12 TDI lifted a 6.0-litre twin-turbocharged engine from the soon-to-arrive Q7. 493bhp meant it had around 80bhp more than the petrol V8 but, more incredibly, it had 738lb ft of torque (a nice, round 1000Nm for those of you dealing in metric) delivered at 1750rpm.

That would allow for a 0-62mph time of 4.2 seconds and a top speed ‘in excess’ of 186mph. Again, 2008 – those were not numbers to turn your nose up at.

Engine aside, the R8 V12 TDI got a much more aggressive bodykit compared with the relatively tame-looking V8 of the time, as well as a fixed rear wing replacing the active element. Oh, and the gigantic roof dam and extended side vents to feed air into the V12.

Audi would bring the concept to Geneva a little later in the year, this time painted red instead of grey. Word began to spread of a small production run being planned, although that never materialised.

Why? Truthfully, we don’t have an answer to give – it just didn’t. Instead, the R8 would receive a 5.2-litre V10 taken from the Lamborghini Gallardo and that would go on to leave its own mark on history.

There was eventually an alternatively-fuelled Audi R8, though – the lesser-remembered, extremely limited production version of the electric E-Tron concept. We suspect Audi’s finance department would like that to continue to be forgotten.