The 24 Hours of Le Mans (French: 24 Heures du Mans) is the world's oldest active sports car race in endurance racing, held annually since 1923 near the town of Le Mans, France. Commonly known as the Grand Prix of Endurance and Efficiency, race teams have to balance speed against the cars' ability to run for 24 hours without sustaining mechanical damage to the car and manage the cars' consumables, primarily fuel, tyres and braking materials. The endurance of the drivers is likewise tested as drivers frequently spend stints of over two hours behind the wheel before stopping in the pits and allowing a relief driver to take over the driving duties. Drivers then grab what food and rest they can before returning to drive another stint. Today it is mandated that three drivers share each competing vehicle.
The race is organised by the Automobile Club de l'Ouest (ACO) and runs on the Circuit de la Sarthe, a circuit containing a mix of closed public roads and specialist motor racing circuit that are meant not only to test a car and driver's ability to be quick, but also to last over a 24-hour period. The competing teams will race in groups called classes for cars of similar specification while at the same time competing for outright placing amongst all of the classes. Originally, the race was held for cars as they were sold to the general public which were then called Sports Cars compared to the specialist racing cars used in Grands Prix. Over time, the competing vehicles evolved away from their publicly available road car roots and today, the race is made of two classes specialised enclosed-bodywork two-seat Prototype sports cars and two classes of Grand Touring cars which bear much closer resemblance to high performance sports cars as sold to the public.