Steve Pruitt doesn't hate gasoline because it pollutes, because it's expensive or because it fosters geopolitical instability. He hates it because it weighs too much. And when the tank on his 680-horsepower racecar runs empty, his driver has to head to the pits to fill it up again.

In a move that's been met with some skepticism in racing circles, Mr. Pruitt, a Utah commercial real estate developer who fields a team in the high-stakes American Le Mans Series, has decided to take on manufacturers like Audi, Porsche and Ferrari...