The Piston Cup is the central racing competition in Pixar's Cars.
The first film follows three racers—Lightning McQueen, Chick Hicks, and The King—as they compete for the Piston Cup championship. A three-way tie forces a decisive race in California, but Lightning's detour to Radiator Springs changes the course of the story.
The competition is modeled on American stock-car racing, especially the culture and presentation of NASCAR. Cars uses fictional teams, sponsors, and tracks rather than reproducing a real championship exactly.
The Piston Cup also links the films across different stages of Lightning's career. Cars 2 places him in the World Grand Prix, while Cars 3 returns to the Piston Cup as Lightning faces younger racers and reassesses his future.