In Pixar’s Cars, Lightning McQueen competes in the Piston Cup series.
The Piston Cup is the film’s main stock-car racing championship. McQueen is a rookie contender who finishes the season tied with The King and Chick Hicks, leading to an unusual tiebreaker race in California.
The championship’s name is a fictional counterpart to real American stock-car competitions. The film uses familiar racing ideas, including pit crews, sponsors, drafting, tire changes, and a season-ending title battle, while giving the competitors personalities and faces.
The Piston Cup is not the same event as the World Grand Prix in Cars 2. The sequel takes McQueen around the world, whereas the original film centers on the Piston Cup and the consequences of his detour to Radiator Springs.