Overview
- The FIA says the maximum geometric compression ratio is 16.0 and confirms it is currently verified with a static procedure at ambient temperature, with no hot-condition testing required.
- Ferrari, Honda and Audi have formally asked the FIA for clarification and are considering a protest at the Melbourne season opener if no resolution is reached.
- Reports allege Mercedes and Red Bull Powertrains use temperature-sensitive components that increase compression ratio in operation while complying in ambient tests.
- Paddock estimates suggest a gain of roughly 10–15 PS, potentially worth up to three tenths per lap under the fuel-limited 2026 hybrid regulations.
- With March 1, 2026 power‑unit homologation approaching, significant redesigns are unlikely, heightening the risk of early-season disputes unless testing rules are adjusted quickly.