Difficulty is a player-set option that determines how tough the opponents in events will be. The options vary depending on the game, and have noticably deproved as the series went on.
Cars: The Video Game Edit
(This is the only game where difficulty differences have seperate categories in the player's records)
- Pro - Story Mode is no matter what set at this difficulty
- Champion - There was rumored to be a cheat code that sets Story Mode to this difficulty, but this was not true
- Practice - Cars: The Video Game is the only game with this mode, it allows players to practice tracks without there being opponents, especially handy on Piston Cup Races where most opponents try to stall the player rather than beat them
Cars: Mater-National Championship Edit
(via Menu Options, Story Mode difficulty can be changed)
- Expert - This difficulty can be unlocked only by entering "VRYFAST" in the Cheat Codes, this also makes Cars: Mater-National Championship the only game to have four opponent difficulties
Cars: Race-O-Rama Edit
Cars 2: The Video Game Edit
- In Fillmore's Fuel Frenzy, difficulty determines how many laps are required to be driven rather than how fast the opposing vehicles are.
- Through modding, it is possible in the second game to make it so different opponents have different difficulties, which this mechanic can be used to determine the opponent's standings more easily or prevent the race from becoming easier when set to rookie.