In Pixar's Cars 3, Lightning McQueen's sponsor before he joins the Rust-eze Racing Center is Rust-eze.
Rust-eze is the bumper-ointment brand associated with Lightning McQueen from the original Cars. In Cars 3, Lightning remains identified with the Rust-eze team while a new generation of high-tech racers threatens his place in the Piston Cup series.
After repeated defeats by Jackson Storm, Lightning trains at the Rust-eze Racing Center. There he works with Cruz Ramirez, whose advanced simulator and coaching methods initially challenge his traditional approach to racing.
Dinoco is a separate racing sponsor and is central to Lightning's early ambitions in Cars. The Piston Cup is the racing championship, not a sponsor, while Octane Gain is another racing-team brand. These names are easy to conflate because they appear throughout the same fictional motorsport world.