MPH: 'Does Mercedes' power unit break F1 rules? It's not as simple as that...'

The Mercedes compression ratio controversy is not fading away as the new season approaches, with the FIA’s Nikolas Tombazis a few days ago saying, “These engineers are very clever and always pushing for an advantage and some have found ways to potentially increase [the compression ratio] when the engine is running hot. And that is the discussion we’re having now.

“We’ve spent a lot of time discussing how we solve those issues. And I think our intention is to solve them for the start of the season. We don’t want to have controversies.

“We want people to be competing on the track and not in the courtroom or in the steward’s room. And that’s what we’re trying to do.”

It’s a nice wish. But with Mercedes bosses reportedly ready to go to court if any late notice regulation change is imposed upon them, it’s not one which is easily granted.

So does the Mercedes power unit contravene the regulations? That’s not a simple yes or no in the real world. It passes the test as written, but supposedly exceeds the compression limit when in operation (when it’s impossible to monitor). But there is a supplementary cover-all line in the regulations (article 1.4) stating that, “F1 cars must comply with these regulations in their entirety at all times during a competition.”

So it’s a slam-dunk, then? If the Mercedes exceeds the compression ratio limit in operation, it is not ‘compliant at all times’ surely? Yes, but as soon as you get into the semantics of that, then you also open the door to, ‘What evidence do we have that it is actually running a non-compliant compression ratio when in operation?’ They are two parts of the same equation and you cannot resolve that equation without answering both sides. The answer to the second part – the one concerning evidence – is ‘none’.

We only have the hearsay (almost certainly accurate, but without evidence still only hearsay) of an engineer who has moved from one engine manufacturer to another and revealed their knowledge of the supposed ruse. That’s the only reason the compliance of the engine is being questioned. Not evidence. Hearsay. If a way could be devised to measure the compression ratio when in operation and it was found to be over, that’s a different matter.

With only hearsay but no supporting evidence with which to prosecute, then we must look at the ‘at all times’ article 1.4. That is, if you believe the cover-all is something to be rigidly applied rather than simply a tool for the FIA to use at its convenience when it wishes to make a change (which is the practical reality).

One area of subverting the regulations, which may have disappeared with the advent of 2026’s active aerodynamics, is that concerning wing flex. But for well over a decade, every single car has exceeded the legal amount of flex when at speed, though complied when measured stationary. So not a single car has been compliant ‘at all times’ in the last decade, probably more. It was impractical to rigidly (sorry for the pun) apply that ‘at all times’ part of the regulation because there was no way of measuring it in action, even though it was absolutely visible from the cameras on the cars.

You see the difficulty in being so fundamentalist on this issue?

Why now insist that a sub-part of the regulation is applied to the letter regarding the Mercedes compression ratio when it hasn’t been applied in this way before? Why is the use of that clause so selective? Well, essentially it’s because the others haven’t worked out how to do it and so are complaining – for competitive reasons. Absolutely not for moral ones. If you believe for one second that if one of Ferrari, Honda, Audi or Red Bull were the only ones understanding how to do this they would refuse to use it, you don’t understand F1.

So because those who ‘have not understood it’, engine manufacturers have the FIA’s own regulatory wording to use as a hammer for their competitive prospects, they are using it as a hammer, trying to force the FIA to act to limit a Mercedes advantage. The teams were in unison in ignoring that ‘at all times’ part of the regulations when they all knew how to subvert the flexi-wing test for years on end. If you can’t beat ‘em, join ‘em. But what if you don’t know how to join ‘em? Then you protest ‘em.

This is not a criticism of those teams. This is just how competitive F1 functions. It’s the field of play.