CHARLOTTE, N.C. — NASCAR apologized today for the tire fiasco that ruined its prestigious race at Indianapolis Motor Speedway and vowed to avoid a repeat.

A durability issue with the tires Goodyear brought to Indy forced NASCAR to call cautions every 10 to 12 laps on Sunday to slow the action and force teams to change their tires before they failed. The longest run under the green flag was 13 laps, and Jimmie Johnson claimed the victory at the end of a seven-lap sprint to the finish in the second-slowest race in the 15 years NASCAR has competed at the Brickyard.

The drivers were disgusted, fans were frustrated and NASCAR is still trying to figure out why things went so wrong.

"I can't say enough how sorry we are and it's our responsibility being NASCAR that we don't go through this situation again," said Robin Pemberton, vice president of competition.

"The race didn't come off like we had hoped, the fans didn't get what they exactly wanted and we'll do everything in our power — it won't happen again, I can tell you that much."

But NASCAR must first figure out why Goodyear's tires struggled so mightily at Indianapolis. The only thing that is certain is that the tire compound Goodyear selected was not strong enough when combined with NASCAR's current car.

The new car is a heavier model that puts significantly more stress on right-side tires, and Goodyear's inventory last weekend couldn't hold up to the pressure.

"It's obvious that we didn't go there with the right car-slash-tire combination," Pemberton conceded.

The problem was exposed in a Saturday afternoon practice session, when some cars couldn't make it three laps without the tire wearing down to the cords. A second practice session was only slightly better, when the runs stretched to about 10 laps before tires began to falter.

Goodyear shipped in an emergency batch of 800 tires it had earmarked for this weekend's race at Pocono, and NASCAR pulled all the crew chiefs together hours before Sunday's start to discuss a strategy for staging a safe race.

Officials decided to throw a "competition caution" 10 laps into the race to examine the tire wear, and promised to continuously monitor throughout the race. With Pemberton patrolling pit road, it became clear the tires wouldn't last much past the 10-lap window unless the abrasive Indy surface began to pick up rubber that would help the tires' traction and extend their wear.

It never happened, as the surface became the equivalent of a cheese grater and the rubber turned into a black dust that made the track even slicker — forcing NASCAR to take control of the race.

"We have to run the race and we have to run the safest race possible, and when we're in situations where we have to take control under adverse circumstances, that's what we do," Pemberton said. "To get ahead of it and have the safest race possible, we had to take control and that's what we did — run 10 to 11 laps at a time and let the cautions fly."