WeatherTech SportsCar Championship

On September 5, 2012 it was announced that the Grand-Am Road Racing sanctioning body would merge with the Braselton-based International Motor Sports Association, and as such, both bodies would merge their premiere sports car series, the Rolex Sports Car Series and American Le Mans Series respectively, with plans to debut in 2014. On November 20, 2012 the merger committee announced that SME Branding were selected to develop the name, logo and identity of the new series.[4]

2014 Sahlen's Six Hours of the Glen

On January 8, 2013, the two series' announced a preliminary class structure for the new merged series. Grand-Am's Daytona Prototype category and IMSA's P2 would combine into a single-prototype class, with allowances for the unique DeltaWing to also compete in the new class. The Le Mans Prototype Challenge class of single spec cars from the American Le Mans Series would continue as is, although the cars will switch to Grand-Am's Continental Tires.[5] The GT class of the American Le Mans Series would remain unchanged, while Grand-Am's GT class will form another GT class, and be combined with the American Le Mans GTC category.[6] The only category of cars not represented in the new series is the American Le Mans Series' P1 category.

The reveal date for the new series was March 14, 2013 at the Chateau Élan Hotel and Conference Center at Sebring International Raceway, two days before the 12 Hours of Sebring. American Le Mans CEO Scott Atherton announced the new sanctioning body would remain IMSA while Ed Bennett revealed the new titles for the series' five classes. SME Branding Senior Partner Ed O'Hara then announced the new United SportsCar Racing title and logo, a name submitted through a contest won by Louis Satterlee of Florida, a racer in the Florida Karting Championship Series.[7]

On August 9, 2013, Fox Sports 1 announced it had signed a TV contract with IMSA to televise the entire USCC season between 2014 and 2018.[8]

Later, on September 12, 2013, Tudor was announced as the title sponsor for the series, which was named the United SportsCar Championship. On August 8, 2015, WeatherTech was announced as the new title sponsor for the series, renaming the series to the WeatherTech SportsCar Championship, starting with the 2016 season.[9]

Beginning with the 2019 season the series is covered exclusively by NBC Sports in the United States. The NBC broadcast network will air nine hours of coverage annually, with the majority of the coverage airing on NBCSN. CNBC and the NBC Sports app will provide supplemental coverage.[10][11]

Originally based on a Canadian series before being acquired by Grand-Am, the Continental Tire Sports Car Challenge (originally known as Grand-Am Cup) is a production-based touring car series. The series is split into two classes known as Grand Sport (GS), intended for large capacity GT-style cars, and Street Tuner (ST), consisting of smaller sedans and coupes, some of which are front-wheel drive. The IMSA Continental Tire Sports Car Challenge until 2013 supported some Rolex Series races but also headlined some of its own dates. This series continued with the United SportsCar Championship after the merger and is somewhat comparable to the old Trans Am Series.

There are five classes in the IMSA SportsCar Championship series, featuring three sports prototype categories and two grand tourer classes:

Sports prototypes:

• Daytona Prototype International (DPi): The flagship class of the championship, featuring cars built to IMSA's Daytona Prototype International regulations, which are based upon the 2017 Le Mans Prototype LMP2 cars. Previously, the DPi's had competed against their base LMP2 counterparts in the Prototype class from 2017-18. The Prototype class had originally consisted of Grand-Am's Daytona Prototypes with the American Le Mans Series LMP2 prototypes, and the DeltaWing, before the original Daytona Prototypes, and the DeltaWing were phased out of competition at the end of 2016, and replaced by the new DPi cars. Starting in 2019 the LMP2 cars were split into a separate Pro-Am class.
• Le Mans Prototype 2 (LMP2): A new class for 2019, it features pro-am driver lineups. The class features cars built by Automobile Club de l'Ouest's (ACO) 4 licensed manufacturers (Riley-Multimatic, Ligier, Oreca and Dallara) to the specifications of the FIA/ACO 2017 Global LMP2 regulations.
• Le Mans Prototype 3 (LMP3): Introduced in the 2021 season, having been in the IMSA Prototype Challenge category as one of the feeder series to the IMSA WeatherTech SportsCar Championship, this class of prototypes features cars built according to ACO's 2020 LMP3 Generation II ruleset specifications from manufacturers such as Ligier, ADESS, Ginetta & Duqueine Engineering.

Grand Touring classes:

• GT Le Mans (GTLM): A continuation of the ALMS GT class, it consists of cars matching the ACO's GTE specification.
• GT Daytona (GTD): a class that combined the Grand-Am GT & GX classes with the Porsche 911 GT3 Cup cars from the ALMS GTC class. Starting in the 2016 season the class adopted full FIA GT3 specifications.

Some races may only use selected classes of cars, for example: Any class car may be permitted entry into the Rolex 24, while at the Grand Prix of Long Beach only the Daytona Prototype International (DPI) and GT Le Mans (GTLM) are entered. LMP2 and GTLM classes are compatible with regulations for the 24 Hours of Le Mans.[12]

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  Nissan Onroak DPi at Petit Le Mans
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  An Oreca 07 LMP2 at Petit Le Mans
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  A Chevrolet Corvette C7.R in front of a Ford GT in the GTLM class at Petit Le Mans
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  Cars from the GTD class at Petit Le Mans