F1 testing 2026: Red Bull are ‘the benchmark’, says Mercedes boss Toto Wolff

Wolff’s remarks come in the context of an ongoing row over the legality of the Mercedes engine.

Rivals believe Mercedes have found a loophole that allows them to run the engine above the permitted compression ratio.

This – a measurement of the cylinder displacement between the two extremes of the piston stroke – is limited to 16:1, and the rules dictate it will be measured at ambient temperature with the engine at rest.

Mercedes’ rivals believe they have found a way to use materials technology and thermal expansion to run the engine to a higher ratio and are pushing for a rule clarification before the start of the season next month.

Mercedes have not denied they are doing this, but insist the engine is legal.

Rivals have claimed the trick is worth as much as 0.3secs per lap, while Wolff said the gain was “a few horsepower – in England you would say a couple, which is more like two and three.”

He added: “Lobbying from the other engine manufacturers has massively ramped up over the last few months.

“I mean, secret meetings, secret letters to the FIA, which obviously there is no such thing as secret in this sport.

“Everybody was a little bit too excited about the performance of the Mercedes engine-powered teams.

“And I think that our colleagues from the other brands have been carried away a little bit that this could be embarrassing, which I don’t think it is at all.”

On the prospect of the rules changing before the start of the season, he said: “There is a governance process. And if that governance were to vote for an engine regulation change, you just have to take it on the chin.”

But he said: “The very essence of Formula 1 is to find performance, to attract the best engineers and the best people, give them freedom to develop regulations and once it goes for you and another time it goes against you.”

Williams team principal James Vowles, who is a Mercedes customer, said: “The PU that we have in the car is completely compliant with the regulations. This is a meritocracy where the best engineering outcome effectively gets rewarded as a result, not punished as a result.

“Right now, I don’t think there is a person in the pit lane that can tell you what is the best PU. We are focused on one detail.

“My hope is that sense prevails and we as a sport recognise that we are here to be a meritocracy. The best engineering solution wins as a result of it and therefore we are where we are right now.”