In Pixar's Cars, Mack is Lightning McQueen's primary hauler and best friend.
Mack is a red truck who transports McQueen and his racing equipment between events. He is voiced by John Ratzenberger, a Pixar regular who has appeared in every Pixar feature film released through the early part of the studio's history.
At the beginning of Cars, Mack is driving McQueen toward California for the Piston Cup tiebreaker race. After becoming exhausted, Mack briefly loses track of McQueen, setting up the story's detour to Radiator Springs.
Mack is often confused with Mater, but they have different roles. Mater is the rusty tow truck McQueen befriends in Radiator Springs, while Mack is McQueen's professional transport truck and longtime companion from the racing world.