CONCORD, N.C. (AP) Jimmie Johnson said Thursday he was ''shocked'' to learn NASCAR was looking into whether his No. 48 team illegally altered the car's side skirts during last weekend's All-Star race.
NASCAR competition officials reviewed the tape and determined Johnson's crew did not make an unapproved adjustment during a late pit stop at Charlotte Motor Speedway. Johnson's team was issued a warning by the sport's governing body but no punishment was levied.
Johnson said NASCAR ''calmed down'' after reviewing video.
NASCAR ''thought there was a lot more intent (with) something going wrong,'' Johnson said.
Side skirts are the sheet metal in front of the rear tires, and unapproved flaring can potentially improve air flow and give a team an unfair advantage. Johnson said the team was repairing crash damage on the right side of the car, not trying to gain an advantage.
Johnson has to be considered one of the favorites to win Sunday's Coca-Cola 600, the longest NASCAR race of the year. He has won the race four times, including last year. He has seven Sprint Cup victories overall at CMS and 13 top-five finishes.
But Johnson doesn't know what to think after what he called a ''less than stellar'' performance at the All-Star race, where he finished 15th and was not a big factor.
''The confidence we normally walk in here with has been diluted,'' Johnson said.
Johnson will be racing a different car this week and plans to use a new setup.
So far, so good.
Johnson was second-fastest in the Thursday afternoon practice session, completing a lap of 191.673 mph. Carl Edwards had the fastest car in practice.
Johnson he said running well in practice doesn't equate to running well at the Coca-Cola 600 since qualifying is in the afternoon and the race starts as the sun is starting set. Cars tend to reacts differently to the track depending on the temperature.
''Practice does not help build confidence in a night race,'' Johnson said. ''We thought we were good in the day last weekend, went to night and didn't have what we needed. This track is tricky. It is tough to get it right.''
More often than not Johnson and crew chief Chad Knaus have gotten it right.
''The 600-mile race has always been good for us,'' Johnson said. ''Chad and I seem to fix our racecar as the night goes on, be aggressive with adjustments, chase the racetrack well and I do a nice job searching for line. The distance of the race doesn't bother me. I think we will have a strong night.''
Johnson's mindset has changed from this time a year ago, when he had yet to win and earn a berth in the Chase for the Sprint Cup.
This year, he's already won three races, securing a spot in the Chase, and has eight top-10 finishes. He is third in the Cup standings behind Kevin Harvick and Martin Truex Jr.