2026 Drama: Alleged engine loophole

[Badger]

Out of curiosity, and ideally without getting too far off topic:

What was Mercedes power advantage estimated to be in 2014 (and any subsequent seasons), objectively defined in HP? 15? 20? Greater than that?

Just curious if there is any way to roughly predict what a 5, maybe 10 HP advantage would manifest as in terms of relative pace during the 2026 season.

As others have rightfully pointed out, this is a different formula, new engines, and cars that (at least now, absent a change in the 50/50 distribution of ICE/electrical power) will be energy starved at times. Presumably that could exacerbate a relative HP difference in PUs, given that more ICE power = more electrical regen (generally speaking)?

But that could be an overly basic interpretation that misses other key considerations. Perhaps there are other critical elements to power generation and recovery that will be equally or more critical than a handful of HP coming via slightly higher compression ratio in the ICE.

Much greater than that. At least 50 HP to the second best engine in 2014, though it's hard to know for sure because they were usually hiding their power and only using what they needed to win comfortably. By 2016 it was much less to Ferrari, maybe 20.

You are correct that one HP on the ICE in 2026 is worth more relatively than in 2014-2025. Before it was usually estimated that 10 HP was worth around 0.15s per lap. Now 10 HP may be worth slightly more, maybe 0.2-0.25s per lap.

[catent]

Out of curiosity, and ideally without getting too far off topic:

What was Mercedes power advantage estimated to be in 2014 (and any subsequent seasons), objectively defined in HP? 15? 20? Greater than that?

Just curious if there is any way to roughly predict what a 5, maybe 10 HP advantage would manifest as in terms of relative pace during the 2026 season.

As others have rightfully pointed out, this is a different formula, new engines, and cars that (at least now, absent a change in the 50/50 distribution of ICE/electrical power) will be energy starved at times. Presumably that could exacerbate a relative HP difference in PUs, given that more ICE power = more electrical regen (generally speaking)?

But that could be an overly basic interpretation that misses other key considerations. Perhaps there are other critical elements to power generation and recovery that will be equally or more critical than a handful of HP coming via slightly higher compression ratio in the ICE.

Much greater than that. At least 50 HP to the second best engine in 2014, though it's hard to know for sure because they were usually hiding their power and only using what they needed to win comfortably. By 2016 it was much less to Ferrari, maybe 20.

You are correct that one HP on the ICE in 2026 is worth more relatively than in 2014-2025. Before it was usually estimated that 10 HP was worth around 0.15s per lap. Now 10 HP may be worth slightly more, maybe 0.2-0.25s per lap.

Good stuff. Thanks very much for the information.

[Badger]

“A significant effort has been invested in finding a solution to the topic of the compression ratio,” the FIA said.

“This parameter, which was one of the key fundamental targets of these regulations in order to attract newcomers to the sport, is limited in the regulations to 16:1, measured in cold conditions.

“The FIA has worked to find a compromise solution which determines that the compression ratio will be controlled in both hot and cold conditions from 1 June 2026, and subsequently only in the operating conditions (130deg C) from 2027 onwards.”

While Mercedes’ rivals have been adamant that the potential gain on offer from the compression ratio trick is as much as 13bhp - which can be worth 0.3–0.4 seconds per lap – Mercedes disagrees.

Team boss Toto Wolff said the gains had been blown out of proportion as he reckoned it was only worth a couple of horsepower at best.

https://www.the-race.com/formula-1/f1-2 ... s-earlier/

[ferkan]

Merc advantage in 2014 was more like 50+ hp, it was huge.

[Farnborough]

It's over. Regulations have been amended and published late yesterday. The language now makes explicit that ANY technique designed to increase the compression ratio above 16:1 in operating conditions is PROHIBITED. Thermal expansion, 2nd chambers, genie in a bottle, all Prohibited. That ends any possibility for Mercedes to work above the compression ratio limit.



https://i.postimg.cc/tJb71LQp/image.png

No it isn't. Thats just two points of detection now defined, outside which its not measured. It's a niave view, and shows even more that rules are hard to write.

Definitely accounts for "tricks" method, device etc by prohibition.

It can't account for the existing, in every engine, thermal, kinetic etc movement of components defined and manufactured within metallurgical performance envelope. Nothing can function without this.

The simplest way to set a reasonable compliance for all the engine manufacturers would be to state 15:1 @ ambient in understanding they wouldn't likely get too high (above 16:1) in practice, and without device/tricks.

Everything MUST have a tolerance, depending on where that's located the outcome will change. McLaren (floor dsq) and Mercedes (under weight) example of running too close to accepted tolerance. That's part of understanding and working with target and tolerance in any competent system.

Anyone given any thought as to how the check @ 130C is going to be quantified ? Whats the tolerance on that temp level ? How is it maintained and measured ? Are tge instruments of measurement also heated ? Do the have complicity a calibrated norm ? At what temperature would the measurement tools conform with their reference ? What is the reference used for this process ? Can it be reliably repeated on demand ?

That asks more questions than gives answers.

[AR3-GP]

It's over. Regulations have been amended and published late yesterday. The language now makes explicit that ANY technique designed to increase the compression ratio above 16:1 in operating conditions is PROHIBITED. Thermal expansion, 2nd chambers, genie in a bottle, all Prohibited. That ends any possibility for Mercedes to work above the compression ratio limit.



https://i.postimg.cc/tJb71LQp/image.png

No it isn't. Thats just two points of detection now defined, outside which its not measured. It's a niave view, and shows even more that rules are hard to write.

Definitely accounts for "tricks" method, device etc by prohibition.

It can't account for the existing, in every engine, thermal, kinetic etc movement of components defined and manufactured within metallurgical performance envelope. Nothing can function without this.

Every manufacturer is on the same page regarding the effects of trivial thermal expansions that affect components. It's impossible to build a PU without such knowledge. It's the engineered solutions with a deliberate intent to go above and beyond 16:1 which have been eliminated by the latest revision.

The latest wording suggest that the FIA can go as far as inspecting drawings to look for components, mechanism, integrated assemblies, and so on that work as defeat devices. Manufacturers will not risk reputational damages by attempting to be dishonest especially when this topic has been so belabored. We're in a different time. The reputational damages are catastrophic, and especially when innocent engine customers are involved. It only takes a single whistleblower employee.

[Badger]

No it isn't. Thats just two points of detection now defined, outside which its not measured. It's a niave view, and shows even more that rules are hard to write.

Definitely accounts for "tricks" method, device etc by prohibition.

It can't account for the existing, in every engine, thermal, kinetic etc movement of components defined and manufactured within metallurgical performance envelope. Nothing can function without this.

The simplest way to set a reasonable compliance for all the engine manufacturers would be to state 15:1 @ ambient in understanding they wouldn't likely get too high (above 16:1) in practice, and without device/tricks.

Everything MUST have a tolerance, depending on where that's located the outcome will change. McLaren (floor dsq) and Mercedes (under weight) example of running too close to accepted tolerance. That's part of understanding and working with target and tolerance in any competent system.

Anyone given any thought as to how the check @ 130C is going to be quantified ? Whats the tolerance on that temp level ? How is it maintained and measured ? Are tge instruments of measurement also heated ? Do the have complicity a calibrated norm ? At what temperature would the measurement tools conform with their reference ? What is the reference used for this process ? Can it be reliably repeated on demand ?

That asks more questions than gives answers.

Measuring at 130degC is very clear, much clearer than "ambient" even. So that's not going to be an issue, and the questions about how it will be done are a bit performative IMO, it's not that hard to heat something to 130degC and measure it.

If your engine is below 16:1 at ambient, and it's below 16:1 at 130degC, the chance that it is significantly above 16:1 in true operating conditions is very small. Then it would almost certainly have to rely on a trick outside of thermal expansion to accomplish that, and such a trick is now strictly prohibited in the new rule.

[Farnborough]

It's over. Regulations have been amended and published late yesterday. The language now makes explicit that ANY technique designed to increase the compression ratio above 16:1 in operating conditions is PROHIBITED. Thermal expansion, 2nd chambers, genie in a bottle, all Prohibited. That ends any possibility for Mercedes to work above the compression ratio limit.




https://i.postimg.cc/tJb71LQp/image.png

No it isn't. Thats just two points of detection now defined, outside which its not measured. It's a niave view, and shows even more that rules are hard to write.

Definitely accounts for "tricks" method, device etc by prohibition.

It can't account for the existing, in every engine, thermal, kinetic etc movement of components defined and manufactured within metallurgical performance envelope. Nothing can function without this.

Every manufacturer is on the same page regarding the effects of trivial thermal expansions that affect components. It's engineered solutions with a deliberate intent to go above and beyond which have been eliminated by the latest revision.

The latest wording suggest that the FIA can go as far as inspecting drawings to look for defeat devices. Teams will not risk reputational damages by attempting to be dishonest, especially those teams who supply multiple customers. The reputational damages are catastrophic. It only takes a single whistleblower employee. We're in a different time.

You've taken the opposite of what I've written.

Defeat devices, absolutely resolved in prohibition by the words they've used.

They are no measuring outside the two method for any other COMPLETELY NORMAL shifts in reality of any engine, neither can they with the two method they've chosen.

16:1 @ both those two measurement method will likely be higher in real world performance. It can't be legislated out of existence. It's real material performance under duress of running these design, and any other ICE design.

[fourmula1]

So parts devices designs used to control compression ratio are still allowed. Just cant be used to exceed 16:1. ???? At the end of the day only the tests matter.

[AR3-GP]

You've taken the opposite of what I've written.

Defeat devices, absolutely resolved in prohibition by the words they've used.

They are no measuring outside the two method for any other COMPLETELY NORMAL shifts in reality of any engine, neither can they with the two method they've chosen.

16:1 @ both those two measurement method will likely be higher in real world performance. It can't be legislated out of existence. It's real material performance under duress of running these design, and any other ICE design.

I understand, but in my opinion the variance between the manufacturers will be very small after these revisions. The test are a little bit for show as you say, but realistically these PUs operate very similarly when everyone designs to the same regulatory intention. In my opinion, it's the language that prohibits defeat mechanisms which is the more important amendment. It's significantly limits what can be done beyond menial thermal expansions.

[LM10]

This shouldn't be a surprise to anyone.

2 weeks ago Toto Wolff confessed and said his team will be affected: https://www.skysports.com/f1/news/12433 ... new-season

2 weeks ago Nicolas Tombazi clarified that they don't want anyone getting cute and 16:1 was there to help the new manufacturers and they don't want anyone to work around it: Compression Ratio, DRS Removal and More - 2026 F1 Regulations: You Asked, We Answered

I posted all of this back then and had to entertain a lot of silly arguments about how clear english wasn't really that clear.

So did I.

It has started with arguments of the rules not being clear (they always were) and went on to arguments of it being somehow impossible to stay within 16:1 even though all but one manufacturer managed it (now it turns out the opposite is the case and the CR decreases while in operation).

[f1isgood]

To summarize,

- Compression ratio decreases as temperature grows from my understanding. As it stands every team is at 16 ambient and as temperature grows they hit 15.x.

Mercedes remains closer to 16 or 18 or whatever than the others, potentially giving them an advantage.

Since compression ratio decreases, every engine will anyways pass the test regardless of temperature. So the tests themselves are meaningless. They change nothing.

But the real question that remains is what is Mercedes actually doing? No one seems to understand that. All we have are broken theories.

Unless the FIA know what to look for, it still remains quite meaningless. I have a feeling Mercedes trick might not be that easy to find.

[motobaleno]

It's over. Regulations have been amended and published late yesterday. The language now makes explicit that ANY technique designed to increase the compression ratio above 16:1 in operating conditions is PROHIBITED. Thermal expansion, 2nd chambers, genie in a bottle, all Prohibited. That ends any possibility for Mercedes to work above the compression ratio limit.



https://i.postimg.cc/tJb71LQp/image.png

In my opinion this will ban (for the future) 100% second chambers. but not thermal expansion of standard components (rod etc). Because for them thermal expansion is not by design but an unavoidable accidental fact. For them only the test will make the law. If they pass the test they will be ok no matter what happens after.
Nevertheless I'm satisfied because the real game changer would be the chamber, with purely thermal expansion of standard components, I don't think the gain would be really important.

In other words with this wording of the rules, the situation has been made perfectly specular to that of the wings.

Another important thing is that this development of the facts does not actually reveal what is the trick that NOW mercedes is using. If actually there is a 2nd chamber now it will be relatively easy, by design, to close it but it will require some time to rebuild the heads for every team. SO in this case, 130 test in june is only smoke and mirror just to gain the time needed to make the modifications to complain with the other part of the new rules.

[AR3-GP]

But the real question that remains is what is Mercedes actually doing? No one seems to understand that. All we have are broken theories.

Unless the FIA know what to look for, it still remains quite meaningless. I have a feeling Mercedes trick might not be that easy to find.

The FIA don't need to find it. Toto Wolff said his team would change the engine. They are not going to be dishonest about it and I believe them.

[f1isgood]

But the real question that remains is what is Mercedes actually doing? No one seems to understand that. All we have are broken theories.

Unless the FIA know what to look for, it still remains quite meaningless. I have a feeling Mercedes trick might not be that easy to find.

The FIA don't need to find it. Toto Wolff said his team would change the engine. They are not going to be dishonest about it and I believe them.

Unless the FIA knows whats up I am very reluctant to trust Wolff. Nothing is stopping Mercedes from running illegal engines as long as the FIA don't know whats illegal about them. I think we all know the FIA well enough.