How The Diesel-Powered Audi R10 Dominated Its Rivals At Le Mans
Audi was coming out of 2005 completely on top of its game. Its gasoline-powered R8 TFSI had won at Le Mans all years between 2000 and 2005 with the exception of 2003. Looking for a new challenge, Audi designed a diesel racing engine from scratch, using the combination of direct injection and turbocharging pioneered on the R8. The diesel engine was an aluminum-block, 5.5-liter V12 with about 650 horsepower. It was both longer and heavier than the gasoline V8 used in the R8, requiring weight savings in the carbon-fiber chassis. To avoid the appearance of a traditional smoking diesel engine, the Audi R10 used diesel particulate filters (DPF) to reduce diesel smoke.
The Audi R10 went on to win at the 24 Hours of Le Mans three years in a row in 2006, 2007, and 2008. The R10s were extremely fast, but they could also make fewer fuel stops, since diesel engines are more efficient than gasoline ones. This turned out to be a winning combination for endurance racing.
The Audi R10 played the long game to win at Le Mans
The diesel-powered Audi R10 is one of the fastest diesel powered cars ever made. It incorporated a short-term overboost feature using turbochargers made by Garrett, and this provided an additional 150 horsepower for overtaking. With this system under its belt, the Audi R10's 2006 Le Mans victory was achieved at an average speed of more than 133 mph.
Audi's decision to choose diesel power for the R10 was a shrewd one, in view of what is really important in racing at the 24 Hours of Le Mans. An endurance race like Le Mans puts extra priority on factors like efficiency, reliability, and the ability to make a few pit stops as possible. The longer you are out on the track, the farther you can go during the 24 hours of the race. The diesel-powered Audi R10's ability to go a greater distance on a tank of fuel, along with its reliability and its speed, let it dominate Le Mans like few cars before it.
One legacy of the diesel-powered Audi R10 — along with its high-pressure, common-rail, direct-injection system — was seen on the roads not long after the R10's third Le Mans victory in the form of the 2009 Audi Q7 V12 TDI Diesel. This large SUV was powered by a 6.0-liter, twin-turbo diesel V12 that produced 500 horsepower. This engine could go 155 mph and reached 60 mph from a standstill in 5.5 seconds. The over-the-top Q7 V12 TDI Diesel made our list of 10 discontinued diesels we wish were still around.