A diesel engine has finally won at the Indianapolis Motor Speedway.

History buffs will remember the Cummins Engine Specials in the early ’50s, one of which with its 6.6-liter oil burner actually sat on the pole for the 1952 Indy 500 but had to drop out following a turbo failure.

Over the weekend, however, a Mazda6 with a SkyActiv-D Clean Diesel won the GX class in the Grand-Am Brickyard Grand Prix. The #70 SpeedSource team with drivers Sylvain Tremblay and Tom Long took the lead with 47 laps remains and held off the Porsche team to claim its fifth straight win in the series.

“We made history today, both for Mazda and for SkyActiv Clean Diesel technology,” says John Doonan, Motorsports director for Mazda North American operations.

Mazda says the production-based 2.2-liter 4-cylinder engine in the racecar is 51 percent stock by parts count and 63 percent by weight. Dyno results indicate 400 horsepower at 5,000 rpm and 445 lb-ft peak torque at 3,600 rpm. The engine features two Garrett turbochargers mounted in series — a GTR 3776R on the low-pressure side and a GTR2560R on the high-pressure side. Fuel system is a common rail, direct injection setup.

You can read more about the SkyActiv-D in this EngineLabs story.