While designed as an F1 engine, the DFV was also used as in endurance racing, although its flat-plane crank design led to destructive vibrations putting stress on devices surrounding the engine, especially the exhaust system. The first sports car to use a DFV, the Ford P68, failed to finish a single race because of repeated mechanical and electrical failures. Despite this handicap the DFV won the 24 hours of Le Mans twice in its original 3.0 Litre form for Mirage and Rondeau, who were able to attain sufficient reliability by de-tuning the motor.