More horsepower, A-post changes and new testing rules for 2026
The 2025 NASCAR Cup Series season just concluded. Now, the sanction is looking forward to the upcoming season with a set of new rules.
View the new NASCAR rules for 2026 below.
As previously announced, NASCAR will increase horsepower to 750hp for tracks under 1.5-miles. The short track/road course package for these tracks will use a a three-inch rear spoiler and fewer diffuser strakes.
Tracks using the 750hp package: Bristol Motor Speedway, Darlington Raceway, Dover Motor Speedway, Nashville Superspeedway and World Wide Technology Raceway at Gateway.
New for 2026, A-post flaps will now be used at every track. The new flaps were introduced in 2025 at Talladega, Daytona and Atlanta.
Additionally, the surface under the A-post flap must be bright orange. The rule previously stated that it needed to be a high-visibility or contrasting color.
NASCAR officially increases horsepower for the 2026 season
New testing rules
The following only applies to me prospective 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.”
– “These 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.”
New sporting rules and procedures will be released in January.
