Clean diesel keeps marching forward, even as American consumers continue to warm slowly to the idea of moving beyond familiar gasoline-powered vehicles. The slow pace is unfortunate considering advanced diesel variants are inherently more fuel efficient than their gasoline counterparts and, might we add, often more fun to drive because of diesel’s copious low-end torque.

How do you convince people to step up to diesel? One time-honored way to create believers in new technologies – and in some cases fuels – is proving them out on the race track. We’re seeing that today at various race venues where electric, hybrid, ethanol, and other alternative fuels or technologies are in competition.

In recent years, clean diesel has been pushed with vigor in racing, most notably with great success by German auto manufacturers. Diesel is not the exclusive domain of the Europeans, though. The latest evidence of this is Mazda’s recently-announced program to champion diesel in GRAND-AM racing’s new GX Class for advanced/clean technologies. Mazda is the only Asian automaker presently committed to bringing advanced diesel technology to the U.S.

Mazda’s 2.2-liter, stock-block SKYACTIV-D four-cylinder diesel engines feature a 14:1 compression ratio, new two-stage turbocharger, and a 5,200 rpm redline. The production engine’s improvements over Mazda's current 2.2-liter MZR-CD diesel engine are considerable, including a 10% weight reduction, 20% reduction in internal engine friction, and up 20% better fuel economy. The racing variant is being jointly developed by Mazda Motor Corporation, Mazda North American Operations, and SpeedSource Engineering.

The actual Mazda model to be powered by the SKYACTIV-D racing engine will be identified after the conclusion of the 2012 GRAND-AM racing season. Dyno testing is ongoing with track testing scheduled for later this year.