Overview
- Multiple reports indicate the August 1 plan has shifted to a compromise introducing cold and hot compression-ratio tests on June 1, with hot-only checks from 2027.
- Any mid-season amendment must still secure six of seven votes across the five power-unit manufacturers plus F1 and the FIA.
- The row centers on claims Mercedes can pass ambient tests at 16:1 yet run a higher effective ratio on track, though Mercedes maintains its FIA-approved design is legal.
- Ferrari, Honda and Audi pressed the FIA for action during testing, with Red Bull later joining calls for tighter, more representative measurements.
- Paddock estimates suggest a gain of roughly 20–25 horsepower or about 0.3 seconds per lap, while David Coulthard has criticized the FIA’s rule-writing as not reflecting real operating conditions.