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:

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 (296.047 km/h)
Cautions: none
Margin of victory: 1 cl
Lead changes: 9

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 (158.58 km/h)
Cautions: 3
Margin of victory: 13.45 sec
Lead changes: 6

Lap Leader Breakdown