McNish remembers racing a diesel Le Mans car: 'You won't believe it'

Originating from a late night discussion in a bar between Audi’s engine guru Ulrich Baretzky and a pair of ACO officials, the engineer decided that the German giant’s R10 successor would not be petrol powered but, for the first time, diesel.

That tentative chat first occurred in 2001, and when Baretzky presented the idea to the Audi board, support wasn’t exactly unanimous – as he remembered in 2016.

“They must have thought I was a little bit crazy,” he says. “Whenever I suggested it to anyone, they looked at me as though to say, ‘You are an honourable man and have been successful, but isn’t that a little bit too much, a little bit too strange?’”

However, the idea would eventually take hold due to its road relevance, a key reason for Audi’s involvement in sports car racing in the first place.

“We wanted to push the sportiness of the diesel,” said Ullrich, “and the best way to do that was through motor sport.”

Once the car was up and running for test sessions, McNish describes the arresting experience of driving the R10.

“When Baretzky said the successor to the R8 was going to be powered by diesel I thought he had been smoking something or drinking too much schnapps. Was it just a PR fad?” McNish recalls.

“We always had a press conference at the Essen show and Frank Biela had just come back from testing the R10 at Vallelunga for the first time. He was the first to drive it and Tom [Kristensen], Dindo Capello and I were sitting there. So what was it like? He just smiled, then said. “You’ll never believe it, guys.” He couldn’t put it into words, because of the torque, the lack of noise. The sensations were so different to what we were used to. I drove that car for the first time at Sebring and there are a few things I remember from that first test.

“We had to increase the dash size for the display of which gear the car was in because I didn’t have a clue, especially on downshifts – you couldn’t hear the revs.

“Also when the air was rushing over your helmet at 200kph all you could hear was the wind noise. We were even thinking about piping engine noise into the ear plugs so the driver had some sort of feedback. We eventually went with a honking great display on the dash and obviously got used to it. But it was just such a change from what we knew.”

In the end, McNish and co managed just fine. Despite the inevitable technological teething troubles, the Scot and team-mates Kristensen and Capello would win on debut at Sebring ’06 with a four-lap margin despite starting from the pitlane.

The car next ran at Le Mans that year, the McNish machine taking pole with the Emanuele Pirro, Biela and Marco Werner No6 R10 entry claiming the win.

It would do so the next two years also – though not widely adapted through the field, Audi had effected its own racing revolution all on its own.

In the age of the Hypercar, turbocharged V6s and accompanying electric motors made up the sea of hybrids in the 23-car strong top-class field at Le Mans 2024 – Baretzky believes that Audi’s boundary-breaking diesel almost tow decades earlier paved the way for the highly sophisticated powertrains of today.