Like all but two of Pixar's feature films (The Incredibles and Up), Cars 2 has been rated G by the Motion Picture Association of America (MPAA).
Films receiving the G—General Audiences rating "[contain] nothing... that, in the view of the Rating Board, would offend parents whose younger children view the motion picture".
Even though all Pixar movies meet that standard, this G rating comes as a real surprise. With all the reported action in Cars 2, I was strongly expecting a PG rating.
(via The Pixar Times)