NASCAR issues offseason rules update for 750 horsepower package, A-post flaps

The NASCAR offseason is in full swing, and that means an update to the rules package for the 2026 Cup Series season. Of course, there is an increase in horsepower at tracks less than 1.5 miles in length. That means a rather significant change.

Among the changes for the next season are five tracks switching from the intermediate package to the short track package. Bristol, Darlington, Dover, Nashville, and Gateway are all going to be run under the new 750-horsepower short-track package.

The NASCAR rules change on those tracks is significant. This means those tracks will have the 750 HP rules and will hopefully put on better racing. These are all tracks that have had trouble with passing for the lead in the Next Gen era. This rules package should help with that issue.

Another update to the rules book has to do with the new A-post flaps. Those are going to be used at every track next season. Those had previously only been used at superspeedways. The flap underneath must be a bright orange color.

“Competition officials also mandated A-post flaps for the Cup Series at every track, starting next season,” NASCAR.com reports. “The body post — which runs from the hood’s edge to the roof along the windshield’s sides — is equipped with a flap designed to deploy in tandem with roof flaps to reduce the possibility of liftoff in the event of a spin.”

NASCAR updates rules for testing

NASCAR has also updated the rules regarding testing. Each series now has a new set of guidelines for new manufacturers.

-A maximum of three tests for new OEMs, with each test limited to a maximum of three affiliated organizations with two vehicles each.
-Tests must be a maximum of two consecutive days each.
-Tests to be completed by March 1
-Tests prohibited at tracks that have been repaved, are new to the schedule, or that will host events within 60 days of the test session.

When the 2026 season starts, there will be a few updates to the NASCAR rules. There are going to be further updates in January, according to NASCAR. This is a standard update that happens every offseason. When a sport changes as much as NASCAR does from one year to another, updates are a necessary part of the process. FNAs should be excited about the horsepower increase, but not too excited.