GT World Challenge is the global GT3 competition run by SRO Motorsports Group — the organisation (originally the Stéphane Ratel Organisation) that created the GT3 category itself. Every car is a production-based supercar built to a common FIA GT3 standard, so brands such as Ferrari, Porsche, BMW, Mercedes-AMG, Aston Martin, Lamborghini, McLaren and Audi race wheel-to-wheel.
What sets it apart is who drives them. The grid is split by driver rating into four classes — Pro, Gold, Silver and Bronze — so seasoned professionals and amateur racers share the same track, each chasing a class title as well as the outright win. Balance of Performance adjustments keep the many different cars closely matched.
The European series is the strongest GT3 field in the world; sister championships run in America and Asia, and their results feed a global GT World Challenge title. Its showpiece is the 24 Hours of Spa, held at Spa-Francorchamps in Belgium and one of endurance racing's great events. For the season's rhythm, see how a race weekend works.