A Mazda6 SkyActiv-D Clean Diesel race car won the Grand-Am-Brickyard in the GX class last weekend, becoming the first ever diesel-powered car to win at the legendary Indianapolis Motor Speedway. Sylvain Tremblay was behind the wheel of the winning car in the three-hour race.

This win was the fifth in a row for Mazda and has seen them move ahead of Porsche after eight of 12 races in the Grand-Am GX manufacturers championship race. If all goes Mazda’s way, it’s set to bag its 24th class win in the American endurance classic, the most recent wins being in 2008 and 2010.

The winning Mazda6 was propelled by a production-based 2.2 litre SkyActiv-D turbodiesel engine. The term ‘production-based’ is not misleading in this case (though it often is), as the motor has a 51% stock by parts count, including the same engine block used in the production cars.

Mazda chose this approach rather than using a pure race-engine because it delivers the most “honest way to demonstrate the quality, durability and reliability” of its cars. Well, I guess honesty really is the best policy.