 From 1981 to 2001, the event was better-known as the Michigan 500, and was held in high prestige.During its heyday of the 1980s, the race was part of Indy car racing's 500-mile "Triple Crown".Between 1968 and 2007, Michigan International Speedway hosted a total of 55 Indy car races, including twenty-two 500-mile events.