2026 Drama: Alleged engine loophole

[Emag]

It’s interesting that they’re pressing down hard on this now. F1 teams typically don’t care unless they really need to damage a strong competitor. Nobody cared about McLaren’s flexi wings before 2024 either.

It’s likely teams think Mercedes is really strong after the data they got from the Barcelona shakedown.

[organic]

It’s interesting that they’re pressing down hard on this now. F1 teams typically don’t care unless they really need to damage a strong competitor. Nobody cared about McLaren’s flexi wings before 2024 either.

It’s likely teams think Mercedes is really strong after the data they got from the Barcelona shakedown.

My thoughts exactly

[jumpingfish]

This thread was started on this forum on December 19th. It's likely that teams were aware of this trick as early as late November. This means the FIA ​​and Mercedes had plenty of time to fix their non-compliant engines. The regulations stipulate a maximum compression ratio, so why on earth did the FIA ​​allow Mercedes to develop with a higher ratio? Just because testing is done under ambient conditions doesn't mean the engine is allowed to operate at different parameters on the track. Use 15:1 when cold and 16:1 in the race—what's the problem?

[Badger]

Nothing would happen unless FIA + FOM sign off on it, even if 4/5 manufacturers have agreed on a hot measurement procedure.

[Farnborough]

This thread was started on this forum on December 19th. It's likely that teams were aware of this trick as early as late November. This means the FIA ​​and Mercedes had plenty of time to fix their non-compliant engines. The regulations stipulate a maximum compression ratio, so why on earth did the FIA ​​allow Mercedes to develop with a higher ratio? Just because testing is done under ambient conditions doesn't mean the engine is allowed to operate at different parameters on the track. Use 15:1 when cold and 16:1 in the race—what's the problem?

They are doing this .... saying 16:1 @ ambient ultimately prevents it breaching 18:1 operational.

Its the pedantic that don't understand reality of tolerance in real world physics that complain.

[CrazyCarperF1]

I doubt any team would pass the compression test at a temperature other than ambient. the rule could simply have had 16:1 as the maximum ratio, but as the rule states at ambient that is the only condition the compression ratio must not exceed 16:1. I don't even see this as a loophole, no manufacturer would read the rule and come to the conclusion that the ratio must never exceed 16:1.

[brakeboosted]

It’s interesting that they’re pressing down hard on this now. F1 teams typically don’t care unless they really need to damage a strong competitor. Nobody cared about McLaren’s flexi wings before 2024 either.

It’s likely teams think Mercedes is really strong after the data they got from the Barcelona shakedown.

My thoughts exactly

There was always a PUAC meeting scheduled after the test. The protests started well before the test. So I don't agree that this is a response to anything seen during the test apart from Red Bull changing their stance on the situation.

[JRodrigues]

I doubt any team would pass the compression test at a temperature other than ambient. the rule could simply have had 16:1 as the maximum ratio, but as the rule states at ambient that is the only condition the compression ratio must not exceed 16:1. I don't even see this as a loophole, no manufacturer would read the rule and come to the conclusion that the ratio must never exceed 16:1.

It does not state that.

[SpecialOps]

Not sure how the heating of the engine really solves anything. I would expect several manufacturers to be over 16:1 due to thermal expansion, and for me that is perfectly normal given how the test has always been done. However, if there's some other trick potentially involving moving parts (seems likely if the 18:1 rumour for Merc is true) that needs to be looked at separately.

Would there be a distinction between someone at 16.5 vs someone at 18? Only if you consider intention which is a dubious standard in F1.

Couldn’t the manufactures have designed it so that when thermal expansion is factored in they are operating at 16:1? To comply with the rules that’s how one would do it and not working from a baseline of 16:1 at ambient.

[pantherxxx]

It's 4 teams vs one. The pressure is huge on the FIA.

The regulations state that the compression ratio cannot exceed 16.0

2. The measuring process to determine said compression was only carried out at room temperatures - leaving a grey area to increase this ratio at higher temperatures.

3. However - and this is key - the regulation outlining the compression ratio and the regulation outlining how it is measured are independent from each other.
There is also a global written regulation stating that all articles must be obeyed “at all times”.
That means, the compression ratio must be 16 at all times regardless of whether it is measured or not.

[dialtone]

Not sure how the heating of the engine really solves anything. I would expect several manufacturers to be over 16:1 due to thermal expansion, and for me that is perfectly normal given how the test has always been done. However, if there's some other trick potentially involving moving parts (seems likely if the 18:1 rumour for Merc is true) that needs to be looked at separately.

Would there be a distinction between someone at 16.5 vs someone at 18? Only if you consider intention which is a dubious standard in F1.

Couldn’t the manufactures have designed it so that when thermal expansion is factored in they are operating at 16:1? To comply with the rules that’s how one would do it and not working from a baseline of 16:1 at ambient.

Apparently that’s impossible. They only have the technology to break the rules, haven’t invented the technology to comply with them yet. To be able to comply with 16:1 they would need to know how to predict thermal expansion and so on… wait…

FIA gonnaget served here. Audi doesn’t care about the sport like Ferrari does, they will take it down if they need.

[pantherxxx]

But even if Mercedes somehow gets away with this, they still poured enormous engineering resources into a trick that’s worth maybe ~10-15 hp and marginally better fuel efficiency at best. It’s an extremely intricate solution, which certainly required a significant resources and investment for R&D under the strict engine budget cap. Other teams simply used those resources in other areas. If they Mercedes doesn't get away with this, which seems more likely now, they simply wasted those resources. It's a huge gamble for them.

[Badger]

Not sure how the heating of the engine really solves anything. I would expect several manufacturers to be over 16:1 due to thermal expansion, and for me that is perfectly normal given how the test has always been done. However, if there's some other trick potentially involving moving parts (seems likely if the 18:1 rumour for Merc is true) that needs to be looked at separately.

Would there be a distinction between someone at 16.5 vs someone at 18? Only if you consider intention which is a dubious standard in F1.

Couldn’t the manufactures have designed it so that when thermal expansion is factored in they are operating at 16:1? To comply with the rules that’s how one would do it and not working from a baseline of 16:1 at ambient.

That's a very conservative interpretation of the rules IMO, especially when the test is well established at ambient.

[dren]

Wasn't the advantage rumored to be or thought to be ~ 0.4s/lap? That's a rather large advantage for Mercedes powered cars. This is a big FIA mess.

[gearboxtrouble]

I think all the others use thermal expansion and RBPT pretty much admitted they were explicitly maximizing that property. The test should serve two things - show that everyone likely exceeds 16 at operating temperature and show if Mercedes is using the rumored thermally isolated 1cc chamber. That seems more a cheat than just maximizing thermal expansion and the FIA is probably going to ban that for 2027 to prevent an arms race in that area while at the same time accepting that the engines will exceed 16:1 at operating temperature due to normal thermal expansion.