Editing Auto racing (section)

===Sports car racing===
{{Main|Sports car racing}}

[[File:2011 FIA GT1 Silverstone 2.jpg|thumb|[[FIA GT1 World Championship|FIA GT1]] at [[Silverstone Circuit|Silverstone]] in [[2011 FIA GT1 World Championship season|2011]]]]
[[File:Audi R18 e-tron quattro at 2013 Le Mans.jpg|thumb|The [[Audi R18]], a [[Le Mans Prototype]] car, during an [[endurance racing (motorsport)|endurance race]]]]

In sports car racing, production-derived versions of two-seat [[sports car]]s, also known as [[grand tourer]]s (GTs), and purpose-built [[sports prototype]] cars compete within their respective classes on closed circuits. The premier championship series of sports car racing is the [[FIA World Endurance Championship]]. The main series for GT car racing is the [[GT World Challenge Europe]], divided into two separate championships: the [[GT World Challenge Europe Sprint Cup]] and the [[GT World Challenge Europe Endurance Cup]]. This series has formed after the folding of the various FIA GT championships.

The prevailing classes of GT cars are [[Group GT3|GT3]], [[SRO GT4|GT4]] and [[SRO GT2|GT2]] class cars. GT2 cars have powerful engines, often exceeding 600 horsepower. However, they have less downforce than GT3 cars and also have less driver aids. GT3 cars are far and away the most popular class of GT cars, with premier racing series such as the [[FIA World Endurance Championship]] and [[IMSA]] both using GT3 as their top class of GT car. GT3 cars have more significant aero than a GT2 car, but also have less horsepower, typically falling in between 500 and 550 horsepower. GT4 class cars have very little aerodynamics and less horsepower than GT3 machinery, typically around 450 horsepower. GT4 typically serves as the last step up to premier GT-class racing.

Other major GT championships include the [[GT World Challenge America]], [[GT World Challenge Asia]], [[Super GT]], and the [[International GT Open]]. There are minor regional and national GT series using mainly GT4 and GT3 cars featuring both amateur and professional drivers.

Sports prototypes, unlike GT cars, do not rely on road-legal cars as a base. They are closed-wheel and often closed-cockpit purpose-built race cars intended mainly for endurance racing. They have much lower weight, more horsepower and more downforce compared to GT cars, making them much faster. They are raced in the 24 hours of Le Mans (held annually since 1923) and in the (European) [[Le Mans series]], [[Asian Le Mans Series]] and the [[WeatherTech SportsCar Championship]]. These cars are referred to as [[Le Mans Prototype|LMP]] (Le Mans prototype) cars with [[Le Mans Hypercar|LMH]] and [[LMDh]] cars being run mainly by manufacturers and the slightly less powerful LMP2 cars run by privateer teams. All three Le Mans Series run GT cars in addition to Le Mans Prototypes; these cars have different restrictions than the FIA GT cars.

Another prototype and GT racing championship exists in the United States; the [[Grand American Road Racing Association|Grand-Am]], which began in 2000, sanctions its own endurance series, the [[Rolex Sports Car Series]], which consists of slower and lower-cost [[Daytona Prototype]] race cars compared to LMP and FIA GT cars. The [[Rolex Sports Car Series]] and [[American Le Mans Series]] announced a merger between the two series forming the [[WeatherTech SportsCar Championship]] starting in 2014.

These races are often conducted over long distances, at least {{convert|1000|km|0|abbr=on}}, and cars are driven by teams of two or more drivers, switching every few hours. Due to the performance difference between production-based sports cars and purpose-built sports prototypes, one race usually involves several racing classes, each fighting for its own championship.

Famous sports car races include the [[24 Hours of Le Mans]], the [[Rolex 24 at Daytona]], [[Spa 24 Hours|24 Hours of Spa]]-Franchorchamps, the [[12 Hours of Sebring]], the [[6 Hours of Watkins Glen]], and the {{convert|1000|mi|km|adj=on}} [[Petit Le Mans]] at [[Road Atlanta]]. There is also the [[Nürburgring 24 Hours|24 Hours of the Nürburgring]] on the famed Nordschleife track and the [[Dubai 24 Hour]], which is aimed at GT3 and below cars with a mixture of professional and pro-am drivers.