The FIA has put the power unit manufacturers on the clock again, launching an e-vote that could tighten how the 2026 compression ratio limit is policed from mid-season.
After a run of Power Unit Advisory Committee meetings, the governing body has formally circulated a proposed amendment that would change the way compliance is demonstrated. Up to now, the compression ratio limit has effectively been assessed at ambient conditions. The new plan would require manufacturers to prove they meet the limit not only in the workshop sense, but also at a defined “running” temperature — specifically 130°C — to reflect what the engine is actually doing once it’s up to heat.
In other words: the FIA wants to measure the thing teams race, not just the thing they present.
The statement from the FIA makes clear this isn’t a back-of-an-envelope tweak. It says the FIA and manufacturers have “collaboratively developed” a methodology to quantify how the compression ratio changes between ambient and operating conditions, and that the approach has already been validated. If approved, the switch would come into force on 1 August 2026.
The timing is the tell.
Mid-season regulation clarifications are rarely neutral, even when they’re framed as measurement and process rather than outright technical limits. Compression ratio is an area where tiny interpretation gaps can snowball into meaningful performance, particularly in a new power unit era where the margins are expected to be slim and the development race relentless. If there’s been any daylight between what’s legal in the garage and what’s effectively achieved on track once thermal effects take hold, this proposal is designed to shut it.
That doesn’t automatically mean anyone’s been “caught”. But it does suggest the FIA isn’t comfortable with the current policing toolset in a world where manufacturers can be extremely creative with how a power unit behaves across its operating window. A requirement to demonstrate compliance at a representative 130°C moves the conversation away from theoretical geometry and towards real-world condition control — which is exactly where technical controversies tend to live.
There’s also a political undertone here that won’t be lost on anyone in the paddock. By running this as an e-vote with the manufacturers, the FIA is effectively asking the stakeholders most affected to sign off on a tougher interpretation of the rules. That can be read as collaborative governance. It can also be read as the FIA daring anyone to oppose something packaged as a common-sense clarification.
The vote is expected back within 10 days, and any change would still need final approval from the FIA World Motor Sport Council — a reminder that even “just methodology” ultimately becomes a regulatory line in the sand once the WMSC stamps it.
What happens next depends on two things: whether the manufacturers see the 130°C requirement as a fair representation of running conditions, and whether anyone believes the implementation date (1 August) is workable without turning the second half of 2026 into a retrospective compliance headache.
Because this is where it gets delicate. If the new method is genuinely just a better measuring stick for the same limit, teams will argue it should be enforceable immediately. If the new method changes the practical reality of what’s permissible — even slightly — then a delayed introduction starts to look like a compromise: enough runway to adapt, but not enough to ignore.
Either way, it’s another reminder that 2026 won’t just be decided by who finds the most power; it’ll also be shaped by who best reads the fine print, anticipates where the FIA will tighten definitions, and avoids getting caught on the wrong side of an interpretation that suddenly becomes explicit.
The FIA says it will communicate the outcome “in due course”. In F1 terms, that means the noise won’t stop until there’s a yes-or-no — and even then, the real argument will be about what “representative operating temperature” means once the sport’s smartest engineers start looking for the next grey area.
