We were once told by an auto writer that "real car people" didn't want green cars. They wanted noise, and roaring engines, and squealing tires. Well, the triumph of diesel-powered race cars at the famed 24 Heures du Mans shows you can have both.

The French carmaker Peugeot placed first and second at Le Mans with their 908 HDI TAP cars. The Audi R15 TDI, which had won last year, took third place in this year's contest. That's a clean sweep in the fastest, longest, most famous endurance race in the world.

How did they do it? Better fuel economy! The higher gas mileage of the diesels meant they had to make fewer pit stops to refuel than their gasoline-powered competitors.

Even over 24 hours, eliminating a pit stop lasting several minutes may be the difference between the winners' podium and a finish back in the pack.

While no Peugeots are sold in the United States, Audi offers the 2009 Audi Q7 TDI clean diesel sport-utility vehicle, and it will soon launch the 2010 Audi A3 TDI turbodiesel hatchback we drove recently and liked.

Regrettably, the old adage, "Race on Sunday, sell on Monday" didn't lead to a street car powered by the Le Mans engine.

Audi killed its R8 V12 TDI diesel supercar project this spring, saying the costs of modifying its 2009 Audi R8 to accept a version of the Le Mans race car's jaw-dropping 6.0-liter twin-turbocharged V12 diesel were just too high for the low projected sales volume.

As a show car, the oil-burning barnstormer had 500 horsepower, impressive in anyone's book. But the torque--at a locomotive-like 738 pound-feet--was stupendous. The whole package return a top speed (in European spec) of more than 180 miles per hour. On its way there, it managed to knock off 0-62 mph--that's 0 to 100 kilometers per hour, kids--in just 4.2 seconds.

But diesel is still derived from petroleum, even if less of it is used per mile. What about racing electric cars, whose power can come from a variety of sources, including renewables like solar, wind, and hydro generators?

The next step would be a Grand Prix solely for electric cars. And it's on its way already, courtesy of TTXGP, the organizers of an electric motorcycle race held last week as part of the Isle of Man Tourist Trophy race.

The electric-motorcycle event even included pit stops, and allowed hot-swappable batteries so competitors could complete two laps of the fabled circuit.

For 2010, say the TTXGP executives, they will add an electric car class. The makers of the iconic 2009 Tesla Roadster all-electric sports car are reportedly interested. If our test drive was any indication, they'll likely have to trade off range for acceleration.

Peugeot 908 HDI at Le Mans 2009

Peugeot 908 HDI at Le Mans 2009

Audi R15 TDI at Le Mans 2009

Audi R15 TDI at Le Mans 2009

[Peugeot photos from Peugeot media website; Audi photo from Audi R15TDI Facebook group; Gizmag]