In an update to the rule book, NASCAR is adding tire tests Aug. 14-15 at Texas Motor Speedway and Oct. 2-3 at ISM Raceway in Arizona.
The Texas tire test is scheduled to have a team each from Hendrick Motorsports, Richard Childress Racing, Stewart-Haas Racing, Team Penske and Furniture Row Racing. The test is to determine tires for the fall playoff race at Texas.
The Phoenix test is scheduled to have a team each from Chip Ganassi Racing, Wood Brothers Racing, Roush Fenway Racing and Joe Gibbs Racing. That test is set to find a tire combination for the 2019 races there.
The Atlanta Motor Speedway tire test will now be Oct. 16-17. It was pushed back from Aug. 14-15.
Also in the rule bulletin:
Effective July 11 in the Camping World Truck Series, NASCAR will use owner points instead of attempts to qualify in determining provisionals.
Also, when Truck qualifying is canceled, two spots (positions 26 and 27 in the lineup) will be awarded based on the fastest combined practice speeds to vehicles not yet assigned a starting spot. The top 25 spots will be determined by owner points. Filling out the final spots will remain the same as stated in the rule book.