Engine problems had different causes

CHARLOTTE, N.C. -- The president of Toyota Racing Development says the engine failures incurred by the three Roush Fenway Racing teams during Sunday's Sprint Cup race at Las Vegas Motor Speedway were unrelated to the problems five Toyota teams experienced on Saturday.

"Not in any way related,'' Lee White said on Monday. "We're going to take 100 percent responsibility for maybe not having all of our ducks in a row with durability testing when we got to the racetrack to be ready for the decisions the teams put the engines through to get ready for qualifying.''

Four teams supplied engines by TRD -- David Reutimann and Marcos Ambrose of Michael Waltrip Racing and Brian Vickers and Scott Speed of Red Bull Racing -- had to switch engines and start at the rear of the field.

Pole-sitter and eventual race winner Kyle Busch also started at the back of the field after switching engines, but his was built by Joe Gibbs Racing.

White said all seven teams supplied engines by TRD likely will go to Atlanta this week with the same new generation engine but with the conservative package -- a thicker lubricant and small mechanical change that determines how much oil stays around the camshaft -- that reduced horsepower by three to four at Vegas.

He blamed the Toyota failures on teams trying to get more horsepower out of the engine for qualifying and practice. Instead of returning to Charlotte, N.C., on Monday he flew to TRD headquarters in California to make sure the issue wasn't a factor moving forward.

"I asked the question this morning if we had all the testing in the world would we have done all this stuff with freezing the engine and heating the oil and all of this stuff we did for qualifying,'' he said. "They said, 'No, we never did it before.'"

Roush Fenway co-owner Jack Roush on Sunday speculated that the new tire Goodyear introduced led to blown engines by Matt Kenseth, David Ragan and Carl Edwards. Doug Yates, who runs the Roush Yates engine program, wanted to wait until the engines were fully examined before commenting.

"I think we misjudged how fast this tire was going to be, and the engine turned more,'' he said. "It's the same spec on the engine that we had all of last year. It wasn't something new or experimental. I had great confidence in it.''

White said that shouldn't have been a problem, noting there was a tire test in December in which all four manufacturers were represented.

"I know [the information] was passed around between us and Gibbs and everybody else with Toyota,'' he said. "Consequently, we would have made sure we didn't have any issues because of extra revs.''

White said he is comfortable moving forward after Sunday in which three Toyotas finished in the top eight -- including two with the more conservative TRD engine -- and eight were in the top 22.

"Just the modest things we did worked,'' he said. "We had zero engine issues. So that certainly is a stepping stone for us heading toward Atlanta.''

David Newton covers NASCAR for ESPN.com.