Chevrolet has confirmed that the problem that prompted it to change all of its engines ahead of this weekend's IndyCar race at Long Beach was connected to the amount of mileage that the engines have covered.
The manufacturer instructed all of its teams to change engines after inspecting the unit that failed in James Hinchcliffe's car during testing at Sonoma last week. IndyCar regulations forbid engine changes except in specific circumstances, meaning that all Chevy-powered cars will be issued with a 10-place grid penalty for Sunday's race.
GM Racing director Mark Kent said that the specific stresses of racing had uncovered a weakness that was not apparent during dyno testing.
"As much as you try to simulate race conditions when you test on the dyno, there is no substitution for racing conditions," Kent said. "Now we've got two races on these engines, and we saw something on one of the engines that concerned us, and we felt that it was in our best interest to change all the engines prior to the race as opposed to have something happen during the race.
"It wasn't for certain that something would happen, but there was enough concern that we thought that was the best thing to do to preserve the race here and not have a car or two or three fall off during the race, potentially. We want to put on a show for the fans here at Long Beach, so we're going to continue to develop our engine and get to that 2000-mile change interval."
Kent said that he is optimistic that the problem will be solved before the next batch of engines reaches the same point in their life cycle.