The Auto Club 400 is a 400 miles long NASCAR Sprint Cup Series stock car race held at the Auto Club Speedway in Fontana, California. Prior to 2005, the race was held in late April or early May, and until 2010, the race was run at a length of 500 miles. When the NASCAR Realignment of 2005 was made, the race was moved to February. The February date stayed until the 2011 season when the date changed to March. After being pleased with the results of the reduction of the track's former fall race date, the Pepsi Max 400, from 500 to 400 miles Auto Club Speedway decided to do the same thing to its spring race.