Dinoco is the fictional fuel company associated with the Piston Cup in Pixar's Cars.
Dinoco is presented as one of the most prestigious sponsors in the racing world. Its distinctive blue branding appears on race cars and at Dinoco gas stations, making the company an important part of the visual identity of the Cars universe.
In the first Cars film, the Dinoco sponsorship is connected with the Piston Cup champion. Lightning McQueen dreams of replacing retiring champion Strip Weathers, also known as The King, as Dinoco's sponsored racer. The film's conclusion complicates that ambition through Lightning's decision to help a competitor.
Rust-eze is a separate fictional product and sponsor associated with Lightning McQueen. This distinction is a common source of confusion: Dinoco represents a coveted future opportunity, while Rust-eze is Lightning's initial sponsor.