Michelin’s four technical partner teams in the GTLM class – BMW Team RLL, Corvette Racing, Porsche North America, and Risi Competizione Ferrari – all have truckloads of data, championship-winning drivers, savvy race strategists, and embedded Michelin tire engineers.
Yet, when it came time to decide which Michelin tire option to use in qualifying and in today’s Mobil 1 SportsCar Grand Prix at Canadian Tire Motorsport Park, there were some hunches, some educated guesses, and some achy-knee weather forecasts factored into the equation.
Michelin offers its technical partner teams three temperature-based variations of its “medium” compound tires.
With track temperatures reaching as high as 115 degrees F (46C) on Friday and a hot, sunny day in the forecast for the race, Michelin partner teams considered both the medium-temperature/medium compound and the high-temperature/medium compound options. “Both tires are really viable options here at CTMP” said Chris Baker, director of motorsport, Michelin North America.
“The GTLM competition is so fierce and the medium/medium has such a wide operating range that it was seen as a means to help qualify well and to manage track position,” said Baker. “On the other hand, the higher temperature/medium tire is very close in opening lap times and will likely be more consistent over a full stint. We believe that both options are very viable.
“Different cars have different chassis needs and driver preferences,” Baker explained. “Our objective is to help each Michelin technical partner team optimize its performance.”
That may be one reason why the competition in the factory-dominated GTLM class has been so incredibly close. In Friday’s second practice session, the top four Michelin GTLM cars were within 43 thousandths of a second and the spread from first to eighth was less than half a second.
Porsche’s Nick Tandy won the pole in the 15-minute qualifying on Saturday afternoon, edging BMW driver Dirk Werner by .028 seconds. The GTLM entries ran between seven and 11 laps in qualifying. All TUDOR Championship cars must start the race using three of the four tires used in qualifying; if the tires are changed after qualifying, the car must start at the back of its class. Three entries elected to change tires – the No. 17 Porsche 911 RSR, the No. 912 Porsche 911 RSR, and the No. 4 Corvette C7.R.
The GTLM class is the only TUDOR Championship category that offers open tire competition. Michelin respects the confidentiality of team strategies and does not disclose which cars are on which temperature/compound. Tire choices may not become obvious until the second half of the opening stint as the two-car factory teams from BMW, Corvette and Porsche may also consider split strategies with one car on each option.