The move to Michelin as IMSA’s sole tire supplier has been met with rave reviews through the four WeatherTech SportsCar Championship classes.
Faster, more durable, and better able to handle multiple tasks at once, Michelin’s tires represent the greatest year-to-year change for IMSA after spending the last five seasons on tires supplied by Continental.
The switch has changed the tone of discussions among drivers and teams, and with some help from leading pilots in the DPi, GT Le Mans, and GT Daytona categories, the tire differences they describe might help one’s appreciation for the newfound performance seen while spectating trackside or watching via NBC Sports.
“The overall grip level has increased, but more than that is the tire allows the car to have a bit more slip angle without it snapping loose,” says reigning DPi champion Eric Curran, who drives the No. 31 Action Express Racing Cadillac DPi-V.R. “The nice thing about driving on the Michelin is, number one, it gets up to speed significantly quicker on an out-lap with new tires.
“And secondly, it just has more lateral grip. Even in braking, I think the braking has improved with the grip, and then like I said, in the turning in a lateral grip, the car allows a bit more of a slip angle to it before it gives way. The consistency of the tire seems to be extremely good, as well. You can run harder on the tire, lean on the tire more, without having it lose traction. It is now a bit of an easier car to drive.”
Making use of the increased cornering capabilities brought to bear by Michelin has opened the door to driving harder and controlling the inevitable slides that follow.
“For me, it’s made the car easier to drive, even though it’s faster,” he said. “I mean, ultimate lap time is quicker than we’ve ever gone, but the car, in my eyes, is easier to drive because you can get more out of it without crossing that unforeseen line where the car wants to break away.
“Our job as a driver is to push to the absolute limit of the car’s ability, and now the ability of the car has increased with this new traction. And you get more confidence to push even harder than you used to with the previous tires. Really, it’s a big change for us.”
Drivers in IMSA’s GTLM class have been accustomed to racing on Michelin tires since the series launched in 2014. They’ve also been familiar with the suboptimal experience of racing atop mixed rubber. Take the Michelins being ground into the track surface, plus the Continentals formerly used by the majority of the field, and inconsistent handling became an accepted norm by all drivers.
Drivers on Continentals had the same complaint; their tires worked best while digging into streaks of Continental rubber worn into the circuit, but with the blend of Michelin added in, ideal acceleration, cornering, and braking was hard to find.
With every WeatherTech Championship driver set to race on Michelins for the near future, the problem of handling issues caused by conflicting tire compounds is finally a thing of the past.
“I think it’s actually going to have quite a big outcome on how you go about your weekend,” said Oliver Gavin, Corvette Racing’s 2016 GTLM champion. “In the past number of years, we’ve had the mix of Continental and Michelin rubber going down, [and at] certain race tracks and certain races, they’ve gone very unusually. Particularly, say Sebring for instance, where the sun goes down and you think that the car and the tire is gonna perform in a certain way and it goes the other way. You think, ‘Oh, that’s a huge surprise for us.’
“So you’ve gotta be looking at how that Michelin rubber is going to rubber up the track. How it’s gonna affect the outcome of the race and your car balance. It’s important.”
Building off of Gavin’s last observation, WeatherTech Championship teams in all classes have learned how to anticipate the changes in track surface grip as the mismatched Continental and Michelin rubber went down. With Michelin outfitting every entry, teams and drivers will go into the Rolex 24 At Daytona, Mobil 1 Twelve hours of Sebring, and the rest of the upcoming rounds with a bit of a predictive unknown in that regard.
“Now that everybody’s on Michelin tires, the track seems to be gripping up,” said Ford Chip Ganassi Racing’s Sebastien Bourdais, winner of the Rolex 24 and the 24 Hours of Le Mans in 2016 in his GTLM Ford GT. “Where before it seemed to be absolutely neutral [handling] and even from start to finish. Now it seems to be gripping up, putting rubber down, and keeping it. So, I think we’ll probably see a bit of a [handling] balance shift through the event. And potentially obviously faster lap times as the track grips up. So, it’s definitely a bit different and something new that we haven’t seen in many years.”
Like the other WeatherTech Championship categories, IMSA’s GT Daytona class has seen an impressive drop in lap times thanks to Michelin’s tires made for the Pro-Am paddock.
Driving the biggest, heaviest cars in the series, with less downforce to keep those tires glued to the track, has become easier, and despite the exceptional differences in performance capabilities, the engineering side of working with the Michelins is surprisingly similar.
“To be totally honest, we’re within a half of a degree on what we run on the cambers,” multiple Rolex 24 winner Andy Lally said of his Magnus Racing Lamborghini Huracan GT3 in comparison to the Continentals. “We’re within a pound and a half of what we run on the tire pressures. The [GTD] carcass is a little bit thicker than the Conti. It retains a little bit more heat, which means it takes a little more time to get up to temperature. It’s very minute differences.”