Three-time defending NASCAR Sprint Cup champion Jimmie Johnson said the "feel" of his #48 Chevrolet betrayed him last Sunday at Auto Club Speedway in Fontana, Calif.
Johnson, who started second in the Auto Club 500, dominated the first green-flag run but faded to a ninth-place finish late in the race.
At least he avoided the engine failures that knocked out his Hendrick Motorsports team-mates, Mark Martin and Dale Earnhardt Jr.
"At the start of the race, the car was really good, but tight," Johnson said. "As we tried to help the car, we actually kept making it tighter. Looking back on it, I really felt like the splitter was on the ground. So we made adjustments to help the front travel of the car to get the splitter off the ground, and it just made the car worse. Come to find out after looking at our travels afterwards, the splitter wasn't on the ground.
"So I kind of steered us in the wrong direction there. We kind of missed it a little bit there and tuned ourselves out, which is not common for the #48 car, but you live and learn, and we have a better idea of what to do this week."
Johnson said his team-mates' engine failures were attributable to a defective batch of valve springs. Those particular springs were used only in the cars of Earnhardt and Martin, not in the Chevys driven by Johnson, teammate Jeff Gordon and those of Stewart-Haas Racing, which is supplied by Hendrick Motorsports.
"We were fortunate on that front," Johnson said. "It appears that a batch of valve springs… got our other two cars, and they literally broke on the same lap. Fortunately, my car and Jeff's car didn't have those in them or the #39 (Ryan Newman) or the #14 (Tony Stewart), and we made it through."by Reid Spencer/Sporting News