Heavily popular in much of Europe to the point they would sometimes outpace gasoline engines, diesel powerplants exists as a niche item in North America. Large-scale interest in diesel powerplants in North America was a by-product of high gasoline prices in 2008. Although gas prices have dropped from impairing highs, many auto companies were still committed to offer diesel engine options. Attached to building small, affordable cars, Japanese auto brand Mazda created an uproar in 2012 when they pledged to include a diesel engine as part of their upcoming Mazda6 sedan and CX-5 crossover vehicle for North American consumers. Part of Mazda’s campaign to convince American and Canadian audiences to the effectiveness of their so-called SkyActiv-D engine took place in sports car racing. After three years, there have been signs Mazda’s diesel marketing tool is running out of momentum.
Since May, it has been rumoured the SpeedSource team fielding Mazda’s diesel-powered prototype effort in the Tudor United Sportscar Championship has been pursuing a change in powerplant. For the past two seasons, Speedsource operated a twin-turbocharged version of the Mazda 2.2-liter SkyActiv-D engine inside a Lola-powered LMP2 category machine. With approval from Mazda’s head office in Japan, Speedsource wants to drop the diesel engine in favour of a gasoline engine. It’s been suggested that a modified version of the turbocharged 2.0-liter four-cylinder by AER from the 2015 Indy Lights series is being eyed by the team.
The Mazda Prototype was first campaigned in 2014 after the merger of the American Le Mans Series and the Grand Am Series. Unlike Audi and Peugeot who found relatively quick success using diesel engine power, Mazda and SpeedSource effort with the race car resulted in limited celebrations over the 2014 and ongoing 2015 sports car series season. To date, the best effort for the Mazda Prototype with the SkyActiv-D diesel has been a sixth-place finish. For the majority of competition, the struggle has been to keep the diesel-powered prototype car running.
Issues on the track with the SkyActiv-D engine is compounded by the fact Mazda has not yet provided a road vehicle with the diesel powerplant. In Canada, the planned release of the 2.2-liter SkyActiv-D engine was for the spring of last year. As of February of 2015, Car FYI received notice from Mazda that the diesel engine program for production cars is still ongoing with "..further development is required to deliver the right balance between fuel economy and Mazda-appropriate driving performance." Further news on the SkyActiv-D engine’s inclusion on the Mazda6, CX-5 or any other vehicle from the automaker for the United States and Canada has not been provided.