In Pixar's Cars 2, what international racing series do the competitors enter?

In Pixar's Cars 2, the competitors enter the World Grand Prix.

The series is organized by Sir Miles Axlerod as a three-race international competition designed to promote Allinol, a new alternative fuel. The races take place in Tokyo, Porto Corsa and London, giving the sequel a much broader setting than the first film's American road story.

Lightning McQueen enters the World Grand Prix, while Mater becomes involved in an espionage plot after being mistaken for an undercover agent. The race and spy story eventually connect through a conspiracy involving the fuel and a group of dissatisfied classic cars.

The World Grand Prix is distinct from the Piston Cup, the domestic stock-car championship central to Cars. Cars 2 expands the franchise into international racing and spy adventure, which is why its competition is often remembered separately from Lightning's original championship.