Bye, Bye, Diesel: Mazda's United SportsCar Prototype Is Getting Gassy

Illustration for article titled Bye, Bye, Diesel: Mazda's United SportsCar Prototype Is Getting Gassy

We loved the Mazda6 Diesel race car that started off in Grand Am’s class for alternative fuels. It’s a diesel! So weird and quirky! Yeah! We even loved hearing that the diesel engine would live on in a United SportsCar P2 prototype. Unfortunately, that P2 has just been slow, so it’s time for a gas-powered engine swap.


According to Sportscar365, IMSA released a bulletin today confirming that Mazda’s Lola prototype is now eligible to run a gasoline engine from Advanced Engine Research (commonly referred to as AER). This means that Mazda’s SKYACTIV SKYACTIV SKYACTIV SKYACTIV SKYACTIV [...] SKYACTIV car will officially drop the -D.

Sorry, fans everywhere who fantasized about powering the car with leftover bacon grease. Surely that sweet Mazda6 is off running Historics somewhere, right?

Many knew that a change had to be on the way when Mazda dropped to running only one P2 at Detroit to focus on future development. The diesel engine in use for this season was based on the Mazda6 diesel road car engine. Rumors of tension between Mazda’s wish for road car relevance versus the need to tweak the diesel engine for more speed hung over every discussion of “why isn’t the Mazda able to keep up?”

“You [can] start with a road car engine, which is our story,” Mazda motorsports director John Doonan told Sportscar365 back in April. “That’s a difficult path, as we’ve proven here, but it also helps us find the limits of those components.”


This isn’t the first time Mazda will be running an AER engine, either.

“Years ago, we developed a bespoke engine with AER and ran it from ’07 until 2012,” Doonan told Sportscar365 two months ago. “There’s that existing motor. Do we work with a new partner? We’re in the midst of looking at all kinds of options.”


Looks like that option is AER after all.

According to the entry list, Mazda is bringing their second car back for the 6 Hours of the Glen next weekend, and both cars are currently listed as running diesel fuel. Sportscar365 posits that they won’t be running diesel for long, however, as the 2017 rule changes for the P2 class won’t allow diesel anymore. How soon will Mazda make the switch? We’ll find out soon.


(Either way, I’m not tasting the fuel next weekend to find out if they’ve made the switch early. Yecch.)

Photo credit: Getty Images

Contact the author at

Share This Story

Get our `newsletter`


Have to give credit to Mazda for what they tried to do, taking a mostly stock component engine and racing it.

For anyone who’s curious what other Mazda powered Lola chassis used the AER engine: