Each year, NASCAR releases updates to technical rules for its series. Friday, NASCAR dropped the technical updates for the Cup Series. Here are the official changes for the 2026 season.

Horsepower

The big one for most fans: NASCAR has increased engine power to 750 horsepower at tracks measuring less than 1.5 miles and on all road courses. Along with the power increase, each car will feature a 3-inch spoiler and fewer diffuser strakes.

Track Package Changes

For the 2026 Season, five tracks will switch from the intermediate track package to the short-track/road-course package. Those tracks include Bristol, Darlington, Nashville, Dover, and World Wide Technology Raceway.

A-Pillar Changes

NASCAR is mandating the addition of a flap designed to deploy in tandem with the roof flaps to reduce the risk of lift during a spin.

Superspeedways

Last season, the teams had to have a contrasting or high-visibility color under the flaps at all superspeedways following the Summer Daytona race. Starting in 2026, those places are mandated to be bright orange.

Testing

NASCAR has implemented a new set of rule book changes for testing procedures for new OEMs entering either of the three National Series (Cup, O’Reilly, Craftsman Truck).

• 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 must 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 sessions

Image Credit: Patrick Vallely