Overview
- All five power unit manufacturers—Mercedes, Ferrari, Honda, Audi and Red Bull‑Ford—approved the measure unanimously, and it was ratified by the World Motor Sport Council.
- From June 1, 2026, the 16:1 compression ratio will be verified in both cold and hot conditions, moving to hot-only testing at 130°C in 2027.
- The update addresses a preseason dispute over cold-only verification that some rivals argued could be bypassed by designs that change characteristics at operating temperature.
- Reports linked the scrutiny to Mercedes, which maintains its units are legal; the company also supplies McLaren, Alpine and Williams.
- The FIA said additional reviews on energy management for the new 2026 hybrid power units will continue, and teams have seven races to adapt before the new checks begin.