Overview
- The federation confirmed combustion chambers are legal if they measure a 16:1 compression ratio at ambient temperature even if the effective ratio rises when hot.
- Mercedes and Red Bull Powertrains are using thermally expanding combustion components to increase in‑use compression, with reports estimating roughly a 10‑horsepower gain.
- Alpine’s 2026 switch to Mercedes supply positions Franco Colapinto to benefit alongside McLaren and Williams, while Red Bull’s approach will extend to Racing Bulls.
- Ferrari, Honda and Audi requested clarifications and now rely on the FIA’s six‑race ADUO audits, which permit extra development if gaps exceed 2% and expand further above 4%, with the first check expected around Miami.
- Engines are not yet homologated, allowing targeted pre‑season tweaks, but major combustion redesigns are widely viewed as unfeasible before 2027 due to validation timelines and cost.