Jimmie Johnson will drive a backup Chevy after wrecking his primary No. 48 car during Friday morning's practice at Kentucky Speedway.
Drivers are getting used to a new asphalt surface and configuration at the 1.5 mile tri-oval along with new NASCAR downforce rules. The six-time Sprint Cup Series champion had posted the second-fastest practice speed (188.121 mph) in 17 laps before his car sustained right-side damage after hitting the wall in turn 4, forcing him to drive a backup car in Saturday night's 400-mile race.
Johnson says he couldn't see where the track was clean, the car wouldn't turn "in the marbles" and he ended up in the wall.