2018 SportsCar Grand Prix

International Motor Sports Association's (IMSA) president Scott Atherton confirmed the race was part of the schedule for the 2018 IMSA SportsCar Championship (IMSA SCC) in August 2017.^[1] It was the fifth consecutive year the event was held as part of the WeatherTech SportsCar Championship and the thirty-sixth annual running of the race.^[1] The 2018 SportsCar Grand Prix was the seventh of twelve scheduled sports car races of 2018 by IMSA, and was the fourth round not held on the held as part of the North American Endurance Cup.^[1] The race was held at the ten-turn 2.459 mi (3.957 km) Canadian Tire Motorsports Park circuit on July 8, 2018.^[1]

After the Sahlen's Six Hours of the Glen 1 week earlier, Filipe Albuquerque led the Prototype Drivers' Championship with 169 points, ahead of Eric Curran and Felipe Nasr with 168 points, and Dane Cameron and Juan Pablo Montoya with 156 points.^[2] With 147 points, the GTLM Drivers' Championship was led by Joey Hand and Dirk Müller with a one-point advantage over Ryan Briscoe and Richard Westbrook.^[2] In GTD, the Drivers' Championship was led by Bryan Sellers and Madison Snow with 155 points ahead of Katherine Legge with 154 points.^[2]

On July 4, 2018, IMSA released the latest technical bulletin outlining Balance of performance for the event.^[3] In P, the Cadillac DPi-V.R received a 0.3 mm larger air restrictor while the Mazda RT24-P and Nissan Onroak DPi received an increase of turbo boost. Additionally, the Cadillac, Mazda, and Nissan received an increase in fuel capacity. In GTLM, the Chevrolet Corvette C7.R received a 0.9 mm larger air restrictor while the BMW M8 GTE received a reduction in turbo boost. In GTD, the Audi R8 LMS and Porsche 911 GT3 R received air restrictor increases of 1 and 3 millimeters, respectively.

A total of 32 cars took part in the event split across 3 classes. 13 cars were entered in P, 8 in GTLM, and 11 in GTLM.^[4] In P, United Autosports were absent. Spirit of Daytona Racing skipped due to a lack of funding.^[5] Tequila Patrón ESM scaled down to a single entry due to a lack of spare engines following the previous round at Watkins Glen.^[6] Ryan Dalziel joined Pipo Derani in the #22 Tequila Patrón ESM entry. In GTD, CJ Wilson Racing, Squadra Corse Garage Italia, Montaplast by Land-Motorsport, HART, Park Place Motorsports, and P1 Motorsports were absent. Scuderia Corsa scaled down to a single entry while the #16 Wright Motorsports made its since appearance since Belle Isle. SunEnergy1 Racing skipped the event after ending their partnership with Riley Motorsports.^[7] Bill Auberlen and Robby Foley returned to the Turner Motorsport entry.

There were three practice sessions preceding the start of the race on Saturday, two on Friday and one on Saturday. The first two 75 minute sessions were on Friday morning and afternoon. The third session on Saturday morning lasted an hour.^[8]

The first practice session took place at 11:30 am ET on Friday and ended with Colin Braun topping the charts for CORE Autosport, with a lap time of 1:07.155.^[9] Kyle Masson crashed the #38 Performance Tech Motorsports Oreca in turn 1 against the tire barriers.^[10] Performance Tech Motorsports later withdrew its entry from the event.^[11]

The second practice session took place at 3:50 pm ET on Friday and ended with Colin Braun topping the charts for CORE Autosport, with a lap time of 1:06.902.^[13]

The third and final practice session took place at 8:30 am ET on Saturday and ended with Colin Braun topping the charts for CORE Autosport, with a lap time of 1:06.712.^[15]

Saturday afternoon's 65-minute qualifying session was divided into three groups.^[8] All three categories had 15-minute individual sessions, and regulations stipulated teams to nominate a single driver to qualify their cars. The competitors' fastest lap times determined the starting order with the grid arranged to put the Prototype and GTLM cars ahead of all GTD entries.^[17]

Pole positions in each class are indicated in bold and by ‡.

Pos.	Class	No.	Team	Driver	Time	Gap	Grid
1	P	54	CORE Autosport	Colin Braun	1:06.315	_	121
2	P	6	Acura Team Penske	Dane Cameron	1:06.540	+0.225	1‡
3	P	85	JDC-Miller MotorSports	Robert Alon	1:06.841	+0.526	2
4	P	10	Wayne Taylor Racing	Renger van der Zande	1:07.093	+0.778	3
5	P	55	Mazda Team Joest	Jonathan Bomarito	1:07.109	+0.794	4
6	P	7	Acura Team Penske	Hélio Castroneves	1:07.272	+0.957	5
7	P	52	AFS/PR1 Mathiasen Motorsports	Sebastián Saavedra	1:07.276	+0.961	6
8	P	22	Tequila Patrón ESM	Ryan Dalziel	1:07.524	+1.209	7
9	P	77	Mazda Team Joest	Tristan Nunez	1:07.684	+1.369	8
10	P	99	JDC-Miller MotorSports	Misha Goikhberg	1:07.827	+1.512	9
11	P	5	Mustang Sampling Racing	Christian Fittipaldi	1:08.009	+1.694	10
12	P	31	Whelen Engineering Racing	Eric Curran	1:08.168	+1.853	11
13	GTLM	911	Porsche GT Team	Nick Tandy	1:13.517	+7.202	13‡
14	GTLM	67	Ford Chip Ganassi Racing	Ryan Briscoe	1:13.831	+7.516	14
15	GTLM	3	Corvette Racing	Jan Magnussen	1:13.934	+7.619	15
16	GTLM	912	Porsche GT Team	Laurens Vanthoor	1:13.955	+7.640	16
17	GTLM	4	Corvette Racing	Oliver Gavin	1:14.080	+7.765	17
18	GTLM	24	BMW Team RLL	Jesse Krohn	1:14.100	+7.785	18
19	GTLM	25	BMW Team RLL	Alexander Sims	1:14.213	+7.898	19
20	GTLM	66	Ford Chip Ganassi Racing	Joey Hand	1:14.228	+7.913	20
21	GTD	15	3GT Racing	Jack Hawksworth	1:15.581	+9.266	21‡
22	GTD	14	3GT Racing	Dominik Baumann	1:16.020	+9.705	22
23	GTD	48	Paul Miller Racing	Bryan Sellers	1:16.386	+10.071	23
24	GTD	33	Mercedes-AMG Team Riley Motorsport	Ben Keating	1:16.417	+10.102	24
25	GTD	16	Wright Motorsports	Michael Schein	1:16.545	+10.230	25
26	GTD	86	Meyer Shank Racing with Curb-Agajanin	Álvaro Parente	1:16.554	+10.239	26
27	GTD	96	Turner Motorsport	Robby Foley	1:16.707	+10.392	27
28	GTD	58	Wright Motorsports	Christina Nielsen	1:16.887	+10.572	28
29	GTD	63	Scuderia Corsa	Cooper MacNeil	1:17.027	+10.712	29
30	GTD	93	Meyer Shank Racing with Curb-Agajanin	Justin Marks	1:17.603	+11.288	30
31	GTD	44	Magnus Racing	John Potter	1:17.610	+11.295	312
32	P	38	Performance Tech Motorsports	did not participate			32
Sources:[18][19]

• ¹ The No. 54 CORE Autosport entry was moved to the back of the P field for starting the race with a different driver than who qualified.
• ² The No. 44 Magnus Racing entry was moved to the back of the GTD field after the team elected to change tires after qualifying.