NASCAR Loosens Rules on Brake Adjustments During Race Weekends

AVONDALE, Ariz. — NASCAR is loosening its rules on what Cup Series teams can do with the brake pads and rotors on their cars, starting this weekend at Phoenix Raceway.

Wednesday, NASCAR told media members that they shared an update with the teams about allowable adjustments after practice and qualifying. Teams can now remove and replace front brake rotors only after Saturday's sessions. They won't be allowed to change any other brake system components during the process.

NASCAR is also allowing teams to inspect rear rotors – per normal procedures – during Sunday's pre-race adjustments. Then, NASCAR will manage any rotor issues found at that time on a case-by-case basis.

This change comes after NASCAR reviewed brake issues that race teams had at World Wide Technology Raceway Gateway. Multiple teams had brake rotor issues during the race.

NASCAR Cup Series managing director Brad Moran also acknowledged the change is coming ahead of a weekend where brake rotor issues could be an issue, especially with the package the Cup cars will be running. They will run a 750-horsepower engine with lower downforce for just the second time at the 1-mile, D-shaped oval. 

Moran said "there is no limit" to changing rotors and pads. Rotors have always been allowable to change if the rotors were damaged but now the pads are good to change, according to him in a radio interview after the change was announced.

Phoenix spring winner Ryan Blaney was one of the drivers who had brake rotor issues at Gateway, prompting the review that led to this weekend's change. Blaney has won the last two Cup races at Phoenix, including that spring race.

Blaney is trying to make up ground on Kyle Larson, who leads the points directly over Denny Hamlin. Hamlin is another driver who had an issue that likely led to the change. 

At Iowa Speedway in August, Hamlin started the race with what he described as a faulty brake package that NASCAR didn't allow them to change. 

Behind Hamlin in points is Christopher Bell, who led the most laps in the spring and won the spring race in 2025. 

Other championship contenders include Chase Briscoe and Joey Logano, who have won a NextGen race at Phoenix – while Larson and Hamlin haven't. 

Blaney and Bell are the odds-on favorites to win this Sunday's race at Phoenix as the drivers who have won four of the last five Cup races at Phoenix. Logano won the other in that span and is right behind Blaney and Bell as the odds-on favorites for Sunday.