Overview
- An A‑post flap designed to reduce lift will be required at every track in 2026, with the fabric specified to be bright orange for visibility.
- Bristol, Darlington, Dover, Nashville and Gateway are designated for the 750‑horsepower short‑track package, marking the first Next Gen deviation from the 670‑hp spacer at these venues, with Bristol, Gateway and Nashville also dropping the intermediate label and using the simplified rear diffuser.
- Prospective manufacturers face capped testing of three sessions completed by March 1, with each test limited to three affiliated organizations and two vehicles each over a maximum of two consecutive days and barred from newly repaved, newly added or soon‑to‑race tracks.
- NASCAR defines a “New OEM” as one absent from the series for the previous five seasons, a provision relevant to RAM’s confirmed 2026 Truck entry and to reporting that Dodge/Stellantis and Honda are evaluating Cup participation.
- Cup backup engines must be declared before each event, are capped at half the number of teams per engine builder with a shared roster, allow one pre‑installed backup per organization and require inspection and sealing if installed off‑site.