On this day in 1987 Michael Andretti set the average speed record for an entire Indy race, coming to a first place finish at the Marlboro 500 at the Michigan International Speedway with an average speed of 171.490 miles per hour (275.986 km/h). Michael Andretti made his debut on the Indy circuit three years earlier, quickly becoming a top competitor. In racing to his quick win at the 1987 Marlboro 500, Andretti benefited from the bad luck of his legendary father,Mario Andretti. When Mario’s engine failed after building a two-lap lead, Michael was able to overtake his dad.
Michael then held off Al Unser Sr. and Bobby Rahal over the final 94 laps to win. Unser finished 9.11 seconds after the winner, edging out Rahal for the number two spot. Rahal held the previous speed record for an Indy race, winning the 1986 Indianapolis 500 with an average speed of 170.722 mph (274.750 km/h).