Toto Wolff reacts furiously to latest 'illegal' claim

Toto Wolff has reacted furiously to the latest speculation that Mercedes' fuel supplier is facing a race against time to homologate its product ahead of the start of the new F1 season.

The Mercedes team principal has already had to contend with suspicion in the compression ratio saga, which is on the brink of reaching a conclusion.

Now Wolff is having to contend with doubts over fuel supplier Petronas and whether it would be able to obtain the certification and homologation for its sustainable fuel to be used by Mercedes-powered teams this season.

The suggestion was that a failure to do so would force Mercedes, McLaren, Williams and Alpine to use a provisional fuel.

Wolff, though, reacted venomously when questioned on the topic during the team principals' press conference staged during the lunch break in between the two four-hour on-track testing sessions at the Bahrain International Circuit.

"This is another of these stories," said Wolff. "We were told the compression ratio is illegal, which is total bullshit, utter bullshit, and now the next story comes up that our fuel is illegal.

"I don't know where that comes from, and it starts spinning again. Maybe tomorrow we're inventing something else that I don't know, has been on the Epstein files.

"[It is] Another nonsense. This is a complicated topic and the process and all of this, but there's just not... I can't even comment."

Wolff passes judgment on potential rule-changing vote

Wolff, meanwhile, has also dismissed concerns over the fact that a vote is due on the compression ratio issue.

Over the winter, it was revealed that Mercedes HPP had developed an engine, which, when running hot, could produce a compression ratio of 18:1, exceeding the limit of 16:1.

The current rules state that the measurement of the compression ratio is done at ambient temperature, which the Mercedes unit would pass, but through the use of heat-expanding metals, could, in theory, increase to 18:1 whilst on track. It would be worth about 0.3s per lap around Australia's Albert Park. 

On Wednesday, at the second Bahrain test, a meeting of the Power Unit Advisory Committee (PUAC) was held, leading to a proposal whereby, from August 1st, 2026, compliance with the compression ratio regulations must be demonstrated not only at ambient temperatures, but also "at a representative operating temperature of 130°C". 

As to whether he would be confident that the Mercedes PU would pass the rules if voted through, Wolff said: "Yeah, for me, the way works.

"Either we stay with the regulations like we are, or the E vote goes ahead on Friday with the proposal that came from the FIA. Both are okay for us."

"We've said all along that this looks like a storm in a teacup, and the numbers which were coming up, you would absolutely understand why somebody would fight it, but eventually, it is not worth fighting. 

"It doesn't change anything for us, whether we stay like this, or whether we change to the new regulations, and it is a process, but we want to be good citizens in the sport, because it doesn't make a big difference.

"With a changed opinion, you can disagree philosophically, you can disagree with it because I believe the regs are there to be made, and you keep the FIA close to you, and that's how it should be. 

"But if you have four other PUMs which are putting immense pressure on the FIA at a certain stage, what do we then have?

"We were pretty comfortable in having a protest in Melbourne, but is this what we want?"