2018 Pirelli World Challenge
The 2018 GT World Challenge is the twenty-ninth season of the Pirelli World Challenge. Patrick Long was the defending champion in the highest class, the GT class. It is the second season sanctioned by the United States Auto Club. The season began on 9 March in St. Petersburg and ended on 2 September at Watkins Glen. It is the first season of the new TCR class, while the TCB class has been removed from the series.
On 25 May 2018, the series announced it had been acquired by the SRO Motorsports Group.
Calendar
On 17 November 2017, WC Vision announced the 2018 calendar. Circuit of the Americas will be the SprintX season opener instead of Virginia. Mid-Ohio and Sonoma were dropped from the schedule in favor of Portland and Watkins Glen. Laguna Seca, which played host for the Touring Car classes season finale weekend in 2017, will not return to the series.| Round | Event | Circuit | Date | Classes | Supporting |
| 1 | Grand Prix of St. Petersburg |  Streets of St. Petersburg, St. Petersburg, Florida | 9–11 March | GT/GTA/GT Cup GTS/GTSA | IndyCar Series |
| 2 | Grand Prix of Texas | Circuit of the Americas, Elroy, Texas | 23–25 March | SprintX GT SprintX GTS TCR/TCA TC | Headliner |
| 3 | Grand Prix of Long Beach | Streets of Long Beach, Long Beach, California | 13–15 April | GT/GTA/GT4/GT4A | IndyCar Series WeatherTech SportsCar Championship |
| 4 | Grand Prix of Virginia presented by Audi Sport | Virginia International Raceway, Alton, Virginia | 27–29 April | SprintX GT SprintX GTS TCR/TCA TC | Headliner |
| 5 | Victoria Day Speedfest at Canadian Tire Motorsport Park |  Canadian Tire Motorsport Park, Bowmanville, Ontario | 18–20 May | GT/GTA/GT Cup GTS/GTSA | Co-Headliner with NASCAR Pinty's Series |
| 6 | Grand Prix of Lime Rock powered by M | Lime Rock Park, Lakeville, Connecticut | 25–26, 28 May | SprintX GT SprintX GTS TCR/TCA TC | Headliner |
| 7 | Grand Prix of Road America | Road America, Elkhart Lake, Wisconsin | 22–24 June | GT/GTA/GT Cup/GTS/GTSA | IndyCar Series'' |
| 8 | 58th Rose Cup Races | Portland International Raceway, Portland, Oregon | 13–15 July | SprintX GT SprintX GTS TCR/TCA TC | Headliner |
| 9 | TBA | Utah Motorsports Campus, Tooele, Utah | 10–12 August | SprintX GT SprintX GTS TCR/TCA TC | Headliner |
| 10 | TBA | Watkins Glen International, Watkins Glen, New York | 31 August–2 September | GT/GTA/GT Cup GTS/GTSA TCR/TCA TC | Headliner |
Entry list
GT/GTA/GT Cup
GTS/GTSA
TCR/TCA
TC
Race results
Championship standings
Drivers' championships
Championship points were awarded for the first twenty positions in each race. The pole-sitter also received one point with the exception of the GTA and GTSA classes. Entries were required to complete 50% of the winning car's race distance in order to be classified and earn points.| Position | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th | 11th | 12th | 13th | 14th | 15th | 16th | 17th | 18th | 19th | 20th | Pole |
| Points | 25 | 23 | 21 | 19 | 17 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 1 |
GT
;Notes:- 1 – Ineligible to score points
GTA
GTS
GTSA
TCR/TCA
TC
Manufacturers' championships
Only those manufacturers who are SCCA Pro Racing corporate members were eligible to receive points toward the Manufacturers' championship. Points were awarded based on finishing positions as shown in the chart below. Only the highest finishing car of each eligible manufacturer earned points for its finishing position.| Position | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | Pole |
| Points | 10 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 1 |