Goodyear wants to know why its tires failed during the NASCAR Sprint Cup race at Indianapolis.

"What we're doing right now is gathering all the data we possibly can to try to explain it," Stu Grant, Goodyear's general manager for worldwide racing, said Friday at Pocono Raceway, where the Cup cars race this week.

Indy turned into a debacle when the right-side tires provided by Goodyear, the exclusive supplier for all three of NASCAR's top racing series, wore out so fast that NASCAR had to keep putting out caution flags every 10 or 12 laps in the Allstate 400 at the Brickyard.

Grant said Goodyear, which held a tire test at the speedway in April, was mystified.

"Our situation is similar to a lot of what the drivers are telling you in that the results that we saw on Sunday were certainly unexpected," he explained. "We went in there with a proven tire, a known quantity. We didn't see anything different in our test data from April to indicate a problem.

"We saw nothing (last) Friday that was out of the ordinary. But, obviously, Saturday afternoon, we realized we could have an issue. ... We sat down with NASCAR Saturday afternoon and again Sunday morning and we all thought the track would come to us just like it always had and would be fine on race day. But that obviously did not happen."

NASCAR officials have publicly apologized, twice, for the chopped up Indy race dubbed by some the "Tiresome 400."

And the drivers were still talking about Indy, even as they began to prepare for Sunday's Sunoco Red Cross Pennsylvania 500 at Pocono, where they raced without serious tire problems in June.

"I've heard some people, different groups, blaming different people," said Jeff Burton, who finished ninth at Indy. "My view of it is that, ultimately, NASCAR has dedicated Goodyear (to build) the tire that we're going to run, so that means NASCAR has some responsibility. But, ultimately, the responsibility rests with Goodyear."

But Burton also gave the tire company some credit for coming up with the right tire combination most of the time in the first full season of NASCAR's all-new Car of Tomorrow, a bigger, heavier vehicle that puts different stresses on the tires than the former car.

"This car is a completely different animal and, for the most part this year, tires haven't been the issue," Burton noted.

The most unexpected thing at Indy was that the grooved, diamond-ground track surface failed to absorb rubber from tires as the weekend went on.

"Realistically, that track did something that we've never seen it do before, and that's not take rubber," said Denny Hamlin, the third-place finisher. "They couldn't have predicted that in practice."

Instead of rubbering the track, the tires gave off a fine black powder that simply blew away. Goodyear engineers were confused.

While saying Goodyear accepts the blame for not getting it right, Grant chalked up the Indy debacle to "the mechanism of wear."

"That is somehow different from what we experienced in '06 and '07," he said. "The whole combination of that tire, the Car of Tomorrow on that racetrack caused that right rear tire to wear like we had never seen before. The fronts were similar to what we had seen in `06 and `07. The wear improved on the front, but the rear never got any better.

Grant said Goodyear has already called the Indy speedway to block out two possible dates for testing this fall.

"We're going to make sure we fix it," he said. "We've got a lot of resources working on this. We've done a lot of modeling. We've got our top chemists working at that. We need to decide, obviously, what we need to do as a tire company to manufacture a tire that's going to work on this car on that racetrack."