In Pixar’s Cars, the competitors pursue the fictional Piston Cup.
The Piston Cup is the championship prize at the center of the film’s opening and ending race. Lightning McQueen, Chick Hicks, and Strip “The King” Weathers are tied before the final race, creating the three-way contest that drives the first act. McQueen’s ambition to win the cup is initially stronger than his concern for teamwork or friendship.
The competition resembles an American stock-car racing championship, with sponsors, pit crews, haulers, and a season-ending title. Dinoco is not the name of the trophy; it is a major sponsor whose sponsorship McQueen wants to obtain. The Dinoco connection is one reason viewers sometimes remember that name instead.
The Piston Cup is a fictional creation for the Cars universe. It should not be confused with the World Grand Prix, the international race series introduced in Cars 2, or the Rust-eze sponsorship that supports McQueen early in his career.