IROC XIII was the thirteenth year of IROC competition, which took place in 1989. it saw the use of the Chevrolet Camaro in all races for the final year, and continued the format introduced in IROC VIII. Race one took place on the Daytona International Speedway, race two took place at Nazareth Speedway, race three ran at Michigan International Speedway, and race four concluded the year at Watkins Glen International. Terry Labonte won the series championship and $204,900. The roster of drivers and final points standings were as follows:

Race results

Race One, Daytona International Speedway

Friday, February 17, 1989 (5) Indicates 5 bonus points added to normal race points scored for leading the most laps. (3) Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps (2) Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps. Average speed: 183.955 mph Cautions: none Margin of victory: 1 cl Lead changes: 9

Race Two, Nazareth Speedway

Saturday, April 29, 1989 (5) Indicates 5 bonus points added to normal race points scored for leading the most laps. (3) Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps (2) Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps. Average speed: 98.54 mph Cautions: 3 Margin of victory: 13.45 sec Lead changes: 6 Lap Leader Breakdown

Race Three, Michigan International Speedway

Saturday, August 5, 1989 (5) Indicates 5 bonus points added to normal race points scored for leading the most laps. (3) Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps (2) Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps. Average speed: 158.343 mph Cautions: none Margin of victory: .47 sec Lead changes: 8

Race Four, Watkins Glen International

Saturday, August 12, 1989 (5) Indicates 5 bonus points added to normal race points scored for leading the most laps. (3) Indicates 3 bonus points added to normal race points scored for leading the 2nd most laps (2) Indicates 2 bonus points added to normal race points scored for leading the 3rd most laps (did not occur in this race so not awarded). Average speed: 111.68 mph Cautions: none Margin of victory: 1.3 sec Lead changes: 1 Lap Leader Breakdown