Which engine type made Mazda's 1991 Le Mans winner unique among overall winners?

Mazda’s 1991 Le Mans winner was unique among overall winners because it used a Wankel engine.

The winning Mazda 787B was powered by the R26B, a naturally aspirated four-rotor rotary engine. Unlike a conventional piston engine, a Wankel uses triangular rotors turning inside specially shaped housings, giving it a compact design, smooth power delivery and a distinctive high-pitched exhaust note.

The 787B’s engine produced roughly 700 horsepower, while the car’s light 830-kilogram minimum weight helped it exploit the regulations. Volker Weidler, Johnny Herbert and Bertrand Gachot drove the No. 55 Mazda to victory, completing 362 laps and giving Japan its first overall Le Mans win.

“Rotary engine” and “Wankel engine” describe the same essential technology here, but Wankel is the more specific name. The achievement remained unique: the 1991 Mazda was the first and only rotary-powered car to win Le Mans overall. New regulations then ended rotary eligibility, making the victory a one-off in the race’s history.