Mack is the semi-truck that transports Lightning McQueen and was his best friend. It's his job to get the Piston Cup racer to the next track on time and in comfort.
He sports the Rust-eze paint scheme and logos, including a cab cap. His trailer is allows Lightning to relax, recoup between races while keeping in touch with his agent on a built-in phone.
Mack thinks of Lightning as a friend, protecting him from the paparazzi and giving advice.
- He is voiced by the only actor who has performed in every Pixar film, John Ratzenberger.
- Mack is a 90's era Mack Truck Superliner semi with a custom trailer.
He came with the decoration for Christmas 2010. Mack is also the one who made the parties: Mack's Holiday Bash ('N' Crash), Mack's Spring Brake Party 2011, and Mack's Summer Car-B-Q. Mack's June Vroom was also a plan, but the plan was cancelled and replaced with Mack's Summer Car-B-Q.