NASCAR's John Darby: major tire change for Sunday's Michigan 400 (Photo: Getty Images for NASCAR)
By Mike Mulhern
After tire problems developed during two days of practice and testing for Sunday's Michigan 400, on the newly repaved two-mile Michigan International Speedway, Goodyear officials and NASCAR executives have announced a change in race tires for the 400 and a special Saturday evening practice session on the new tires.
Here's the Goodyear release:
"Based on the higher than expected speeds NASCAR Sprint Cup Series teams ran in pre-race practice on the newly repaved Michigan International Speedway, The Goodyear Tire & Rubber Company has decided to change its left-side tire recommendation for Sunday’s race.
"In the final Sprint Cup practice on Friday afternoon, Greg Biffle ran an average speed in excess of 204 mph for his fastest lap. For comparison’s sake, when Goodyear tested at Michigan in preparation for this race on April 3-4, the fastest average lap speed topped out in the 198-mph range. The higher speeds caused significantly higher left-side tire temperatures, which caused Goodyear to take this step.
"The tire code that teams will now run (D-4020) features a tougher tread compound, a different construction and different mold shape than the tire teams ran in practice. The replacement tire was run at Charlotte Motor Speedway after that track was repaved at the end of the 2005 season. This code was run at both races at Charlotte in both 2006 and 2007.
"When Goodyear decided to bring a new tire to Charlotte for the 2008 season, a quantity of this code was built as part of the back-up plan that Goodyear has in place for every race track on the circuit. Since this tire proved durable and provided an ample amount of grip for the repaved Charlotte surface, it made it a logical choice to be put in place for just this type of situation for the fresh asphalt at Michigan.
"Goodyear will ship in enough tires for teams to have 10 sets of tires for the race, which is the original NASCAR set limit for this event. Teams will run their original allotment of right-side tires (D-4528) in Sunday’s race. Teams will have additional tires available for a NASCAR-scheduled practice following the Nationwide Series race on Saturday.
“We decided this move was best to provide quality racing here on Sunday,” said Greg Stucker, Goodyear’s Director of Race Tires. “In collecting data and speaking with drivers and crew chiefs throughout the practice days, we had two choices to make. Our first option was to make the team’s race sets available to them before practice on Friday and allow them the chance to ‘scuff’ them, in order to run them through a heat cycle to increase heat resistance. We did that, but after all the practice sessions ended on Friday, we concluded the safer option was to go to our contingency plan and bring in the 4020s.
" “This code has been run before under similar track conditions and we have full confidence that it will give drivers and teams the enough grip to run a great race on Sunday, while doing so in the safest possible manner. Safety is always our No. 1 concern, and by bringing this tire here this weekend, we will accomplish that goal.”