Toto Wolff didn’t bother with diplomacy in Bahrain. With Mercedes back in the spotlight for all the wrong reasons during 2026 pre-season testing, the team principal unloaded on the swirl of claims around the sport’s latest technical flashpoint: the so-called compression ratio saga.
The nub of it is this: the FIA has confirmed an e-vote among the seven members of the Power Unit Advisory Committee (PUAC) on whether to introduce a new compression ratio test methodology. If approved, it would come into force from August 1. It’s a significant mid-season lever to pull in the first year of a new power unit era — and it’s being discussed because rivals believe Mercedes has exploited a grey area in how the current measurement is conducted.
Wolff’s response to the insinuation that this makes Mercedes’ power unit “illegal” was characteristically unfiltered.
“We were told that compression ratio is something that we were illegal, which is total bulls**t, utter bulls**t,” he said, before rolling his eyes at the way the narrative has escalated over winter.
The PUAC, which brings together the five power unit manufacturers along with the FIA and Formula One Management, has been dissecting this over recent months. Mercedes, by Wolff’s own admission, is isolated among the manufacturers in resisting the direction of travel — a familiar political position for a team that has spent the last decade either setting the pace or, when it isn’t, becoming the reference point everyone wants reined in.
What’s striking isn’t just the ferocity of Wolff’s language; it’s the extent to which this dispute is really about how Formula 1 chooses to govern itself when the margins are small and the incentives to “clarify” are enormous.
Wolff framed it as a philosophical argument: if a component has been developed to the regulations and the interpretation has been accepted, the idea that competitors can then collectively apply pressure for a late rewrite is, in his view, a slippery slope — even if he’s realistic enough to know it’s how F1 has always operated.
“Formula 1 is a meritocracy, and we don’t want any balance of performance,” Wolff said. “I think that philosophically we need to stick to it. You’ve developed the component to the regulations, and that’s been confirmed.
“Then everybody else gangs up and says it’s illegal, the regulator is being put under pressure. Is that how it should go? Philosophically, I disagree, but that’s what has happened the last 50 years in Formula 1.”
There was an edge to the punchline, too — an acknowledgement that these aren’t rules being written in a vacuum. “This time, we were on the receiving end,” Wolff added. “I guess next time, maybe, we will be ganging up against somebody else because we believe it’s not right.”
That’s the part worth underlining. The sport talks a big game about stability and cost control, but the politics of performance are still what they’ve always been: if you believe a rival has found something you can’t copy quickly, you question it — loudly — and you push for a test that catches it. The language is always “fairness” and “compliance”. The intent, usually, is to stop someone scoring points.
Senior paddock sources have suggested that all five manufacturers would currently pass compression ratio tests both at ambient temperatures and at the operational temperatures being proposed. In other words, this isn’t being sold as a targeted ban. But that doesn’t make it neutral.
A change in test conditions can still shift where the line sits, and therefore who gets caught by it — particularly when the vote is set to trigger a new protocol in-season. Wolff has already signalled Mercedes will “take it on the chin” if a change is voted through, but he’s clearly not prepared to accept the idea that the team has done anything wrong in the first place.
He also raised a more technical concern that will resonate with engineers more than politicians: if the FIA tightens the protocol, it has to avoid simply creating a different loophole. Wolff’s preference is for compliance to be required at both cold and hot conditions, rather than swapping one test for another and risking a scenario where a power unit can satisfy the rule at one temperature but not the other.
“I think the way it’s being done now, it needs to be compliant to the regulations when it’s cold and when it’s hot,” he said. “It doesn’t give anybody an advantage…”
The broader context here is that Mercedes has been dealing with more than one fire at once. Alongside the compression ratio chatter, there has also been speculation that Petronas — Mercedes’ fuel partner — is struggling to get its sustainable fuel certified for 2026 use under the FIA’s criteria. Wolff was just as dismissive of that storyline, bundling it into what he sees as a winter of opportunistic noise around his organisation.
“Now the next story comes out that our fuel is illegal!” he said. “I don’t know where that comes from, and it starts spinning again.”
Wolff’s irritation boiled over into gallows humour as he mocked the idea that the rumour mill would simply move on to the next invented scandal. It didn’t quite land cleanly in the room, and even Wolff seemed to realise he’d taken the joke too far in the moment — but the outburst said plenty about Mercedes’ mood right now.
This is a team that knows exactly how exposed it becomes when it’s perceived to be ahead — or even just accused of being ahead — in an area others can’t easily verify. And in 2026, with power unit architecture and operating windows back at the heart of performance, the stakes attached to a “measurement methodology” argument are enormous.
If the e-vote goes against Mercedes and the protocol changes from August 1, the enforcement mechanism matters almost as much as the rule itself. Manufacturers wouldn’t be able to pre-emptively change parts based on their own internal assessments; they’d have to be found non-compliant by the FIA at an event before receiving permission to revise their power units.
It’s a structure designed to prevent teams gaming the system — but it also sets up the possibility of a very public flashpoint later in the year, should anyone fail the FIA’s checks.
For now, Wolff is left arguing for first principles in a paddock that rarely rewards them. In F1, the purity of “meritocracy” only survives for as long as the rest of the pitlane agrees you’ve earned it. When they don’t, it tends to end up where this one has: in a committee, on an e-vote, with the calendar ticking down to August.
