Great Machines: Letter From The Editor: Diesel Smokes Competition
06/01/2006
The most incongruous sounds at this year’s 12 Hours of Sebring—the kickoff of the new ALMS season—were those that emanated from the Number 1 and Number 2 cars, both of which happened to be new Audi R10s. Powered by a 12-cylinder biturbo diesel engine that generates 650 hp and 811 ft lbs of torque, the R10 is extremely quiet by racecar standards, especially when compared to the cacophonous Corvette C6Rs and Porsche 911s.
But while a quiet diesel engine may contradict expectations, diesels perform most of their combustion inside the chamber—when the valves are closed—not halfway out the end of the exhaust pipe, as evidenced by the flames that shoot from many gasoline-powered racecars. The Corvette, to cite one example, still plugs along with ancient pushrod technology, and it does so in dramatic, ear-splitting fashion.
Not Audi. No, the two R10s led most of Sebring’s highest class, and they did so in style—without boasting of their dominance through decibels. It was such a civilized victory that if the field of cars had been running only Audi diesels, the Sebring, Fla., locals might not have known a race was going on. A diesel-only race would have sounded more like the gentle bustle of freeway traffic.
Then again, had they all been Audis, the race might have been close. For most of the day, the two Audis led, and, naturally, one of them ended up winning (the Number 1 car bowed out after track debris blocked part of its intake and caused it to overheat). But throughout the day, lap after countless lap (and there are quite a few laps over a 12-hour race), awaiting the leader to round the track, the entries from Ingolstadt would slip past unnoticed. By the time one of these sports cars is in front of you on the front straightaway, all the eye sees is a silver blur.
Without much further ado, Audi will introduce the world to the first sports car with a clean-burning diesel engine. Look for it to debut later this year as the R8 model hits the streets. But for now, durability testing continues. If you listen very carefully, you may even hear one at a racetrack near you.