2026 Drama: Alleged engine loophole

[Badger]

It does not change the fact that the CR must not exceed 16:1 at all times. It’s simple as that really. If the measurement is what counts, Ferrari’s 2019 engine was as compliant as Mercedes’ current one.

Double standards… no other explanation.

Incorrect, the FIA have a measurement process to enforce this rule and it specifies ambient temperature. Same way we don’t disqualify cars with flexi-wings if they pass the static load test. Same way we don’t check cylinder volumes at operating temperatures, because they would be above 1600cc.

Ferrari tampered with the fuel flow sensor, there was a rule expressly prohibiting this. Totally illegal.

CR must not exceed 16:1 at all times. Period. Not hard to interpret. Read it again.

Rear wings have dots to measure flexing while in motion. Added in 2021 to prevent flexing after passing static load tests.

What will the FIA do in case of CR? Because you know, there is a rule, read my first sentence again.

Dots or not the wings flex, you must have seen the front wings last year. This is against the rules if you take a literal interpretation, but the static load test is the de facto rule because everyone understands wings can’t be infinitely stiff. Same with the ambient CR test and thermal expansion.

I guess they can lobby to change the measurement same way as has been done with static load tests, but the FIA doesn’t have to change it. The engines will be legal as the rules are written now, take it to the bank.

[koolway]

It does not change the fact that the CR must not exceed 16:1 at all times. It’s simple as that really. If the measurement is what counts, Ferrari’s 2019 engine was as compliant as Mercedes’ current one.

Double standards… no other explanation.

Incorrect, the FIA have a measurement process to enforce this rule and it specifies ambient temperature. Same way we don’t disqualify cars with flexi-wings if they pass the static load test. Same way we don’t check cylinder volumes at operating temperatures, because they would be above 1600cc.

Ferrari tampered with the fuel flow sensor, there was a rule expressly prohibiting this. Totally illegal.

CR must not exceed 16:1 at all times. Period. Not hard to interpret. Read it again.

Rear wings have dots to measure flexing while in motion. Added in 2021 to prevent flexing after passing static load tests.

What will the FIA do in case of CR? Because you know, there is a rule, read my first sentence again.

The rule is pretty explicit, and it's not "At all time"

No cylinder of the engine may have a geometric compression ratio higher than 16.0. The
procedure which will be used to determine this value may be found in the Appendix to the
Technical and Sporting Regulations.

You're living in a static "perfect" world, the real world is not like that. Everything moves, compresses, dilates, ... at different rates, cascading through materials,...

Everything vibrates, the more refined your measurement is. There's no such things as definite dimension.
That's why in basic sciences you use STP/NTP conditions to measure things.
That's why FIA sets conditions to measure the compression ratio.
That's why in machining you use gauge blocks being the same material as the one you're measuring in order to cancel different thermal expansion.
That's why you should use gloves to make measurements under 20 microns.

Rear wings have dots to ensure the deflection is within boundaries. Not to make sure they don't move. Otherwise at the first pebble on the road, every team would be DSQ...

In a perfect world, rules would be simpler, but it's not the case

[Hoffman900]

A PhD friend joked to me “infinite stiffness is for undergrads, grad school is when the real fun starts”

[Badger]

Ferrari tampered with the fuel flow sensor, there was a rule expressly prohibiting this. Totally illegal.

Ferrari did NOT tamper with the fuel flow sensor. Any idiot could do that and even those at the FIA would likely spot it. Ferrari had a pulsed fuel flow that was synchronised with the fuel flow sensor's sampling, which I think was 2000 times per second, so it was a rather clever trick and getting it to work an impressive achievement. That said, its purpose was to get around the fuel flow limits so no surprise when the flow rate monitoring was changed to prevent it.

BTW, there has been a long standing rule expressly forbidding the burning of oil as fuel, but that didn't stop it from being a decisive factor when the last major engine rule change was introduced.

[Edit: Sorry Schumix, I missed your post above, but I agree completely.]

I misspoke, the rule doesn't talk about tampering with the fuel flow sensor, it just explicitly bans anything that tampers with the fuel flow.

5.10.5 Any device, system or procedure the purpose and/or effect of which is to increase the flow
rate or to store and recycle fuel after the measurement point is prohibited.

What you describe (which is not confirmed, I've heard other reporting) would not be allowed.

Anyways, I reject the comparison because there are different rules and procedures surrounding these two stories. The "exploit" in this compression saga is not much of an exploit at all, it's just following FIA testing procedure.

[bluechris]

Dial back the outrage a bit and actually look at the facts. The FIA has come out and explicitly said that the measurement procedure has remained the same. They added verbiage to the regulations for clarification, but they did not change the procedure. It was always ambient.

It does not change the fact that the CR must not exceed 16:1 at all times. It’s simple as that really. If the measurement is what counts, Ferrari’s 2019 engine was as compliant as Mercedes’ current one.

Double standards… no other explanation.

Incorrect, the FIA have a measurement process to enforce this rule and it specifies ambient temperature. Same way we don’t disqualify cars with flexi-wings if they pass the static load test. Same way we don’t check cylinder volumes at operating temperatures, because they would be above 1600cc.

Ferrari tampered with the fuel flow sensor, there was a rule expressly prohibiting this. Totally illegal.

Where exactly you got that concrete info? care to elaborate please?

Anyway, we keep beeting a dead horse here. In no way FIA will do anything as matter Toto, never did and never will. This is a fact after all this years.
Yeah maybe to throw dust in the eyes of everyone, will ban it from next year or they will do something else fancy but nothing will huppen this year. If it was Ferrari, RB, AM etc, is another story.

[LM10]

The rule is pretty explicit, and it's not "At all time"

No cylinder of the engine may have a geometric compression ratio higher than 16.0. The
procedure which will be used to determine this value may be found in the Appendix to the
Technical and Sporting Regulations.

Article C1.5 says engines must comply “in their entirety at all times during a competition”

The rule you cited specifies the CR limit without exceptions for higher temperature. Measuring it at ambient temperature is just a procedure and not a green light for higher ratios at operational conditions.

You're living in a static "perfect" world, the real world is not like that. Everything moves, compresses, dilates, ... at different rates, cascading through materials,...

I don’t live in a static world. Rather in a world with rules. The rules state the CR to not be higher than 16.0 and in combination with article C1.5 this means at all times during competition. In order for this to be the case, your CR must be lower at ambient temperature. Not so hard to understand and totally compliant with a “real” world.

Rear wings have dots to ensure the deflection is within boundaries. Not to make sure they don't move. Otherwise at the first pebble on the road, every team would be DSQ...

The static load tests combined with the reference points in the wings and high res cameras ensure pretty accurately that the flex stays within given limits. I don’t think a wing flexing half a mm more than another will give a competitive advantage. Let’s talk about pedantics…

[LM10]

Incorrect, the FIA have a measurement process to enforce this rule and it specifies ambient temperature. Same way we don’t disqualify cars with flexi-wings if they pass the static load test. Same way we don’t check cylinder volumes at operating temperatures, because they would be above 1600cc.

Ferrari tampered with the fuel flow sensor, there was a rule expressly prohibiting this. Totally illegal.

CR must not exceed 16:1 at all times. Period. Not hard to interpret. Read it again.

Rear wings have dots to measure flexing while in motion. Added in 2021 to prevent flexing after passing static load tests.

What will the FIA do in case of CR? Because you know, there is a rule, read my first sentence again.

Dots or not the wings flex, you must have seen the front wings last year. This is against the rules if you take a literal interpretation, but the static load test is the de facto rule because everyone understands wings can’t be infinitely stiff. Same with the ambient CR test and thermal expansion.

I guess they can lobby to change the measurement same way as has been done with static load tests, but the FIA doesn’t have to change it. The engines will be legal as the rules are written now, take it to the bank.

Wings are allowed to flex and there are specific limits which are being measured not only in static load tests, but also when in motion via reference points and high res cameras.

If the FIA is too incompetent to measure the CR at operating temperature, they could force teams to prove them that their PU is within rules. I don’t think it’s rocket science.
They asked Ferrari for help in 2019, for example.

[Badger]

CR must not exceed 16:1 at all times. Period. Not hard to interpret. Read it again.

Rear wings have dots to measure flexing while in motion. Added in 2021 to prevent flexing after passing static load tests.

What will the FIA do in case of CR? Because you know, there is a rule, read my first sentence again.

Dots or not the wings flex, you must have seen the front wings last year. This is against the rules if you take a literal interpretation, but the static load test is the de facto rule because everyone understands wings can’t be infinitely stiff. Same with the ambient CR test and thermal expansion.

I guess they can lobby to change the measurement same way as has been done with static load tests, but the FIA doesn’t have to change it. The engines will be legal as the rules are written now, take it to the bank.

Wings are allowed to flex and there are specific limits which are being measured not only in static load tests, but also when in motion via reference points and high res cameras.

If the FIA is too incompetent to measure the CR at operating temperature, they could force teams to prove them that their PU is within rules. I don’t think it’s rocket science.
They asked Ferrari for help in 2019, for example.

Aerodynamic surfaces can't be designed to move for aerodynamic reasons, yet that is exactly what flexi-wings are. According to the literal interpretation of the rules it's not allowed, but both you and I can see that there is a need for pragmatism in that scenario. The question is why you can't understand the same concept when it comes to the engine and thermal expansion? Sure as the sun rises the engine will change its dimensions slightly depending on the temperature, so if the FIA has specified that the engine be measured and homologated at ambient temperatures that seems like a very pragmatic solution, no?

[hollus]

Is anyone thinking that all engines stay below 1600cc when hot?

[Badger]

Is anyone thinking that all engines stay below 1600cc when hot?

Engine cubic capacity must be 1600cc (+0/-10cc).

Logically the engine cannot satisfy this rule at both ambient and operating temperatures. So there we have another one of these where the FIA needs to specify when the measurement should be made, and no one questions it because it makes sense.

[LM10]

Dots or not the wings flex, you must have seen the front wings last year. This is against the rules if you take a literal interpretation, but the static load test is the de facto rule because everyone understands wings can’t be infinitely stiff. Same with the ambient CR test and thermal expansion.

I guess they can lobby to change the measurement same way as has been done with static load tests, but the FIA doesn’t have to change it. The engines will be legal as the rules are written now, take it to the bank.

Wings are allowed to flex and there are specific limits which are being measured not only in static load tests, but also when in motion via reference points and high res cameras.

If the FIA is too incompetent to measure the CR at operating temperature, they could force teams to prove them that their PU is within rules. I don’t think it’s rocket science.
They asked Ferrari for help in 2019, for example.

Aerodynamic surfaces can't be designed to move for aerodynamic reasons, yet that is exactly what flexi-wings are. According to the literal interpretation of the rules it's not allowed, but both you and I can see that there is a need for pragmatism in that scenario. The question is why you can't understand the same concept when it comes to the engine and thermal expansion? Sure as the sun rises the engine will change its dimensions slightly depending on the temperature, so if the FIA has specified that the engine be measured and homologated at ambient temperatures that seems like a very pragmatic solution, no?

Going the lengths of designing your engine to have a significantly higher compression ratio while in operation is one thing and giving your best to stay within limits (and accepting minimal changes due to thermal expansion) is another. Sure as hell the FIA could enforce tests to prove what the intent was.

[koolway]

Article C1.5 says engines must comply “in their entirety at all times during a competition”

The rule you cited specifies the CR limit without exceptions for higher temperature. Measuring it at ambient temperature is just a procedure and not a green light for higher ratios at operational conditions.

You're making too much assumptions. The rule specifically detail how they will assess the value of the compression ratio at all time during an event.
--> At ambiant temperature.

The procedure which will be used to determine this value may be found in the Appendix to the
Technical and Sporting Regulations.

I don’t live in a static world. Rather in a world with rules. The rules state the CR to not be higher than 16.0 and in combination with article C1.5 this means at all times during competition. In order for this to be the case, your CR must be lower at ambient temperature. Not so hard to understand and totally compliant with a “real” world.

The sole existence of any measurements procedures contradicts your argument.
If you don't want any ratio above 16:0 when running, make it 2:0 at ambiant temperature....
The rule is not well written for its intent (if you make the bold assumption that the intent was to measure the compression ratio of the running engine)
Spoiler alert : the rule is not written like that, therefore making that assumption is just a leap of faith...

Bodywork measurement clearly states :

3.2.2 .... all aerodynamic components or Bodywork must be rigidly fixed and immobile relative
to their defined Frame of Reference defined in Article 3.4. These components must also
provide a uniform, solid, hard, continuous, and impervious surface at all times....

In order to ensure that the requirements of Article 3.2.2 are respected, the FIA reserves the
right to introduce further load/deflection tests on any part of the bodywork which appears to
be, or is suspected of, moving whilst the car is in motion.

Engine measurement don't make that distinction, making appendix measurement procedure at ambiant temperature final for all compression ratio during an event.

The static load tests combined with the reference points in the wings and high res cameras ensure pretty accurately that the flex stays within given limits. I don’t think a wing flexing half a mm more than another will give a competitive advantage. Let’s talk about pedantics…

If you don't want to be precise about real world physics, rules wording and what is NOT defined. Maybe the technical aspect of F1 is not the best suited for you...
Ever heard of marginal gains? any marginal gains is part of a competitive advantage whatever their values.
It's not being pedantic, it's about not making assumptions when none must be made.
Why would the FW endplate body must not have a curvature radius less than 5mm ? at 5.01mm you're DSQ ...
Why would the FW bodywork deflection must not exceed 15mm at measured points ? at 15.01mm you're DSQ...

Those are the rules, argue the rules are bad and you could have done better all you want.
But a team of highly competent engineers make them. On the opposite side, you have 11 teams of hundreds of engineers who try to find any marginal gains.
Don't hate the players, hate the game...

[LM10]

If you don't want to be precise about real world physics, rules wording and what is NOT defined. Maybe the technical aspect of F1 is not the best suited for you...
Ever heard of marginal gains? any marginal gains is part of a competitive advantage whatever their values.
It's not being pedantic, it's about not making assumptions when none must be made.
Why would the FW endplate body must not have a curvature radius less than 5mm ? at 5.01mm you're DSQ ...
Why would the FW bodywork deflection must not exceed 15mm at measured points ? at 15.01mm you're DSQ...

Comparing a body part dimension to a wing flexing is weird, but OK.

Actually it's amazing you tell me about marginal gains when it's me who tells you that instead of allowing significantly higher compression ratios the FIA should do their best to ensure that the rules are being followed. Both parties should do their best up to the point where changes due to real world physics must be accepted.

Using the argument that in real world physics with thermal expansion the compression ratio will always be higher than at ambient temperature (which of course is true) to condone Mercedes' intent of specifically increasing the compression ratio by a significant amount, is absolutely ridiculous.

[koolway]

Comparing a body part dimension to a wing flexing is weird, but OK.

Actually it's amazing you tell me about marginal gains when it's me who tells you that instead of allowing significantly higher compression ratios the FIA should do their best to ensure that the rules are being followed. Both parties should do their best up to the point where changes due to real world physics must be accepted.

Using the argument that in real world physics with thermal expansion the compression ratio will always be higher than at ambient temperature (which of course is true) to condone Mercedes' intent of specifically increasing the compression ratio by a significant amount, is absolutely ridiculous.

I'm comparing rules, deviation from the rules, and the impact of that deviation (DSQ if your measurement is outside the allowed boundary).

A wing shouldn't flex, but it inevitably does. So it has to stay within the boundaries defined by the measurement procedures.
A compression ratio will inevitably vary with temperature, so it shouldn't exceed what is permitted under the measurement procedures.

The FIA actually tried to be more transparent by including this in the rulebook, improving on 2025 where these measurements were handled through scrutineering procedures and Technical Directives. Those were not public, and according to various sources, compression ratio measurements were always done at ambient temperature.

It's not that different from saying a wing may deflect a maximum of 15mm when 100kg is applied to the tip, but will deflect 25mm if you apply 102kg.

That’s why regulation drafting is difficult and never really finished.
Either you make rules immutable eg : “wings cannot flex under any conditions” > and then everyone gets disqualified the moment a fly touches the bodywork.
Or you base them on real-world physics and define acceptable tolerances.

And as soon as one area becomes airtight, teams will shift their focus to another area where performance can still be found. That's what F1 technical side is all about...

[Badger]

Wings are allowed to flex and there are specific limits which are being measured not only in static load tests, but also when in motion via reference points and high res cameras.

If the FIA is too incompetent to measure the CR at operating temperature, they could force teams to prove them that their PU is within rules. I don’t think it’s rocket science.
They asked Ferrari for help in 2019, for example.

Aerodynamic surfaces can't be designed to move for aerodynamic reasons, yet that is exactly what flexi-wings are. According to the literal interpretation of the rules it's not allowed, but both you and I can see that there is a need for pragmatism in that scenario. The question is why you can't understand the same concept when it comes to the engine and thermal expansion? Sure as the sun rises the engine will change its dimensions slightly depending on the temperature, so if the FIA has specified that the engine be measured and homologated at ambient temperatures that seems like a very pragmatic solution, no?

Going the lengths of designing your engine to have a significantly higher compression ratio while in operation is one thing and giving your best to stay within limits (and accepting minimal changes due to thermal expansion) is another. Sure as hell the FIA could enforce tests to prove what the intent was.

So you don't think the front wings that bend like a banana were designed with that intent?