Doc Hudson was a three-time Piston Cup champion before retiring in Pixar's Cars.
Doc's racing career took place in the early 1950s, when he competed as the Fabulous Hudson Hornet. He won three Piston Cup championships, in 1951, 1952, and 1953, and recorded 27 wins in a single season. His racing number was 51, matching the Hudson Hornet's famous real-world association.
After a severe crash and an indifferent response from the racing world, Doc left competition and eventually became Radiator Springs' doctor and judge. He initially hides his racing history from Lightning McQueen, but later helps train the young racer. The character was voiced by Paul Newman in the original Cars.
Doc is distinct from The King, who is the reigning champion in the first film, and Chick Hicks, Lightning's aggressive rival. Doc's career also draws on the real Hudson Hornet, a celebrated stock car in early NASCAR history, while the Piston Cup itself remains fictional.