Audi’s V12 TDI is One of the Most Interesting Engines Ever Made
A story of how motorsport dominance, greed, and a little bit of wanting to show off resulted in a bi-turbo diesel V12-powered SUV.
Audi over the decades has produced a myriad of stunning and unique engines from its iconic inline-5 to the monster V10 featured in the R8. Some that honestly have not gotten the proper appreciation that they deserve. One thing few people understand is Audi’s deep and long relationship with motorsport. Thanks to Mike Duff on Pistonheads, we get some context for this amazing time in Audi’s history.
This ever-continuing journey in competition has allowed the brand to fund and develop the engine technology seen in Audi’s model lineup, whether that is recognized or not. See, Audi has had an extremely dominant presence in the what is considered by many to be the world’s greatest race, the 24 Hours of Le Mans.
After some intense lobbying by manufacturers keen to push their wares into motorsport, it was decided to allow diesel engines to compete under LMP1 endurance racing regulations. Audi had been one of the biggest campaigners for this, being very keen to demonstrate the credentials of its TDI technology.
Since 2000, Audi has racked up a total of 13 victories in the top LMP class, providing them an insane win percentage of 63% since the turn of the century. This is stunning in itself and Audi would as a result forever be cemented in motorsports history as one of the greatest and most successful manufacturers.
Another thing about being successful is that success is very lucrative in motorsport. Winning means money and money means the potential for some questionable spending. Enter the V12 TDI.
How the hell was this approved?
There was, however, a marketing problem. Beyond some overlapping fuel injection tech, the mid-engined racecar had almost nothing in common with Audi’s diesel road cars of the period. Something which frustrated Audi’s senior management to the extent that they ordered – as our Prime Minister would probably put it – the spaffing of many more millions to develop a road-going version of the motor.
In 2021 hindsight, even the thought of a V12 turbo-diesel engine in a SUV might be considered shameful. It was a bold statement by the brand back in the early 2000’s, but now it almost seems ridiculous. So here is why that was even considered an acceptable thing to approve.
Audi at the time had a very successful V12 TDI-powered car called the R10 TDI, which would go on win Le Mans 3 years in a row. As we mentioned before, Audi’s engine tech usually trickles down from their motorsport developments. In this case, the higher ups wanted to see the winning engine in a road car.
That is when the problems started. Dumbing down a V12 built for racing is hard enough, there is only so little complexity you can take out of something with that many cylinders. Throw complex turbo-diesel technology in the mix and you have a project that was questionable for mainstream production from the start.
Why the Q7 SUV became the ideal choice to fit a V12
Initially, the obvious choice for the engine was the R8 supercar, but fitting an engine as large and intricate in such a tight place ended up being impossible. No surprise there, as the car would have to have been essentially redesigned from the ground up to host such a radical engine.
The next vehicle in line? You guessed it: an SUV, the Q7. From a packaging perspective, this was one of the few cars that could actually fit an engine this complex and heavy. Was Audi expecting this to be a big seller or reshape the luxury SUV market? Surely not.
At the time, the uber-luxury SUV market didn’t exist as it did today and the focus in automotive technology was drastically different. It is likely Audi realized they had already spent so much many developing the engine to be put in a production car, they felt the obligation to see it through.
One of the worst-selling and rarest Audis, period.
The actual V12 that ended up gracing the engine bay of the Q7 was a faint memory of the engine found in the R10 race car. Even the diesel technology was different. It truly was move to save face for the company at this point. However, the Q7 still ended up being while questionable, extremely interesting.
The V12 would go on to make 493 HP and 738 ft/lbs of torque, a ridiculous figure for any vehicle in this class regardless of price or brand, even today. It truly was unique. Not to mention, it could make hundreds of ft/lbs of torque over the advertised figure, but was limited by the sloppy 6-speed automatic gearbox.
It sold terribly, only about 50 units over the full course of production of 4 years. Audi expected 40 units a year at the starting price of $132,000. However, they also did not expect the global financial crisis of 2008 either, the year the V12 went into production. Unfortunately, the V12 Q7 was destined to fail.
It is much more expensive than the plentiful V6 and V8 TDI versions, of course – but it’s hard to argue against the price given the exclusivity. How often do you get the chance to buy a genuine one-off?
An enigma stuck within a bubble we will never to be seen again
The Q7 V12 TDI was never sold in the U.S. and very few people have ever even see this mythical beast out on the road anywhere in the world. They truly are a needle in a haystack. Some supercars have larger production numbers than this Q7. As one can imagine, the aftermarket support for the engine is nearly non-existent and few Audi dealerships will have ever seen or worked on this particular engine.
That is what makes it so interesting. There was never any reason to build this vehicle, but Audi did anyway. Whether it was to prove their dominance in diesel technology or justify their spending in motorsport to their board, the vehicle will live as a timeless reminder of an era we will never return to.
Photos: Audi
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