NASCAR Sprint Cup drivers have given mixed reviews to the new tire specification Goodyear has brought to Michigan in an attempt to prevent the blistering that occurred at the venue earlier this year.
Goodyear was forced to make a tire specification change during the series' last visit to the two-mile oval in June, following blistering issues caused by the unexpectedly high speeds Cup cars ran on the newly paved surface. Last month 27 Sprint Cup teams tested a new specification tire formulated by Goodyear in attempt to find a better compromise between the original soft tire and its harder replacement.
The left-side tire for this weekend will use the same compound as the harder tire raced back in June, although the construction of the tire has changed. The right side meanwhile features a slight reduction to the tread thickness.
Reigning Sprint Cup champion Tony Stewart believes the changes will effectively limit where drivers can find grip on the circuit, which may eventually lead to little side-by-side action during Sunday's race.
"The biggest difference right now is that we haven't run the soft tire this weekend to get a bunch of rubber on the race track so it's really hard," said Stewart following Friday's practice. "I mean it's one lane wide right now. It's going to take a lot to get it any wider than that."
Jeff Gordon believes the track doesn't have as much grip this weekend as it had back in June, which leads him to think that the original specification brought by Goodyear would have been fine this time.
"I feel like that track's lost a little bit of grip, so I feel like now the old tire would've been just fine," said the four-time champion. "But we don't know until we get into race pace and see the heat, and I'm sure there's still a chance of blistering.
"I think we all know that racing on the harder tire and this combination is the best thing. So far, it's hard to tell. This construction seems to be pretty good with this compound, it's just not optimal for what we've been dealing with today."
Ryan Newman, who was among those testing the new compound at Michigan last month, says the new harder compound has helped avoid any blistering issues.
"According to what we came up here and tested it was the same and everything felt good," said Newman. "I think there are no issues at all with the tires. I guess the only issue you could say is they don't really wear out, but that's on the safety factor right now with the new asphalt."
Sprint Cup teams will get a further chance to run on the new tire specification during Saturday's practice session ahead of Sunday's 400-mile event at Michigan.