Pre-Season Engine drama

[Nitrodaze]

Rumour has it that Mercedes has built a monster engine, and Redbull have a similar concept. It is looking like a Mercedes Engine dominance is coming. This may be good for McLaren, but I suspect Mercedes may be the team to beat if the rumour is correct.

I am curious to see how the Ford engine in the Redbull hold up to the competition. Car giant Ford have alway built championship-winning F1 engines in the past, but times have changed as Honda found in the early stages of their return to F1.

I wonder if the championship is going to be fought between the Mercedes-powered cars. The Ferrari may have chassis challenges to overcome, but I expect the Ferrari engine to be up there with the Mercedes. The embarrassment that Ferrari has suffered in the 2025 season may drive them to produce a better car that may surprise everyone. They obviously need more than a better car to win championships. The need to carry out a major overhaul of their operation side, l feel.

[F1nKS]

For those who may not know what is going on. Mercedes has found a loophole that allows them to run their engines at a higher compression ratio (18:1 vs. 16:1). This will ultimately give them approximately 15 HP greater. RB may also be going down this path.

The other engine makers (Ferrari, Honda, and Audi) are asking FIA to intervene before the season and stop it.

If the FIA changes its procedures for evaluating engines, the RB and Mercedes could be crippled. FIA had pushed out a compromise that they will run with the 2026 rules and then change them for 2027. Ferrari is said to have filed a protest.

[Used to be Starter]

For those who may not know what is going on. Mercedes has found a loophole that allows them to run their engines at a higher compression ratio (18:1 vs. 16:1).

KaBoom!

[Steve Boyd]

I've also seen a rumour that Adrian Newey has found a loophole that gives more downforce than should be expected from the new chassis/floor regulations. We could be in for a repeat of the Brawn double-diffuser protests and appeals as well as an argument over engines.

[Nitrodaze]

For those who may not know what is going on. Mercedes has found a loophole that allows them to run their engines at a higher compression ratio (18:1 vs. 16:1). This will ultimately give them approximately 15 HP greater. RB may also be going down this path.

The other engine makers (Ferrari, Honda, and Audi) are asking FIA to intervene before the season and stop it.

If the FIA changes its procedures for evaluating engines, the RB and Mercedes could be crippled. FIA had pushed out a compromise that they will run with the 2026 rules and then change them for 2027. Ferrari is said to have filed a protest.

Well said buddy :-)

[airshifter]

For those who may not know what is going on. Mercedes has found a loophole that allows them to run their engines at a higher compression ratio (18:1 vs. 16:1). This will ultimately give them approximately 15 HP greater. RB may also be going down this path.

The other engine makers (Ferrari, Honda, and Audi) are asking FIA to intervene before the season and stop it.

If the FIA changes its procedures for evaluating engines, the RB and Mercedes could be crippled. FIA had pushed out a compromise that they will run with the 2026 rules and then change them for 2027. Ferrari is said to have filed a protest.

Alleged cheating, alleged advantage. At this point it's nothing more than claims really.

And I fully expect this to be less messy in terms proving compression ratio, but just as if not more messy in terms of proving that they knew it would be deemed illegal if found and are by that reasoning cheating. Just like with the Ferrari fuel flow loopholes, it might be simply too hard to prove.

And I suspect that if the FIA clamps down hard on the Article 1.5 basis that "Formula 1 cars must comply with these regulations in their entirety at all times during a competition"..... well the only compression ratio testing during the competition takes place in the pits, at ambient temps. To introduce another test is to change the regs, and I might add that if they decided on a way to heat the engines to near operating temps, the other teams might have higher CRs as well. Intentional or not, if they break 16:1..... but wait, they can't do that because they have already changed the regulation to allow that testing. It's a slippery slope.

I personally think the reduction in compression ratio was done on insane theory already. If Audi or anyone else new doesn't want to invest in figuring that out, they weren't that invested in F1 to begin with, and we shouldn't reduce the potential output to appease them and make it easier.

Hard to say how it will all go down, but the most recent precedent I can think of is DAS. And even though it was known that DAS existed based on a loophole, the FIA let Merc run it for the year, as well as allowed others to develop it if they wanted. But with engine homologation a different beast, the FIA might be in a position to deem it simply legal or not.

[Nitrodaze]

Alleged cheating, alleged advantage. At this point it's nothing more than claims really.

And I fully expect this to be less messy in terms proving compression ratio, but just as if not more messy in terms of proving that they knew it would be deemed illegal if found and are by that reasoning cheating. Just like with the Ferrari fuel flow loopholes, it might be simply too hard to prove.

And I suspect that if the FIA clamps down hard on the Article 1.5 basis that "Formula 1 cars must comply with these regulations in their entirety at all times during a competition"..... well the only compression ratio testing during the competition takes place in the pits, at ambient temps. To introduce another test is to change the regs, and I might add that if they decided on a way to heat the engines to near operating temps, the other teams might have higher CRs as well. Intentional or not, if they break 16:1..... but wait, they can't do that because they have already changed the regulation to allow that testing. It's a slippery slope.

I personally think the reduction in compression ratio was done on insane theory already. If Audi or anyone else new doesn't want to invest in figuring that out, they weren't that invested in F1 to begin with, and we shouldn't reduce the potential output to appease them and make it easier.

Hard to say how it will all go down, but the most recent precedent I can think of is DAS. And even though it was known that DAS existed based on a loophole, the FIA let Merc run it for the year, as well as allowed others to develop it if they wanted. But with engine homologation a different beast, the FIA might be in a position to deem it simply legal or not.

I think they may have a tough time proving the compression ratio is illegal. Afterall, teams are using very similar alloys for the conrod and piston. And these things would expand under increased temperatures. That said, no one knows what materials Mercedes is using for their engine parts. It would be a sad day if regulations started specifying what materials should be used for all engine components.

I wonder how such an engine would work on the desert race tracks.

[Nitrodaze]

I've also seen a rumour that Adrian Newey has found a loophole that gives more downforce than should be expected from the new chassis/floor regulations. We could be in for a repeat of the Brawn double-diffuser protests and appeals as well as an argument over engines.

Bring on pre-season testing, l say.

[airshifter]

I've also seen a rumour that Adrian Newey has found a loophole that gives more downforce than should be expected from the new chassis/floor regulations. We could be in for a repeat of the Brawn double-diffuser protests and appeals as well as an argument over engines.

Well I haven't seen the mention of what Newey might have found, but just forum members on F1Technical have found loopholes in the aero package regs that seem would easily change the idea of outwash being unlikely. I'm sure a guru like Newey has been deep into just about any possibility.

[airshifter]

I think they may have a tough time proving the compression ratio is illegal. Afterall, teams are using very similar alloys for the conrod and piston. And these things would expand under increased temperatures. That said, no one knows what materials Mercedes is using for their engine parts. It would be a sad day if regulations started specifying what materials should be used for all engine components.

I wonder how such an engine would work on the desert race tracks.

I suspect that *IF* we ever find out that the rumors are true, the metals that expand will be used in very limited areas. As you say, all metals expand with temperature, but for the most important areas this has been factored in so that the engine is at it's best under full operating temperature. As such bores, pistons, rods, valves, bearings would likely not change over how they were designed. Otherwise it would probably result in either increased engine wear or excess friction.

BUT we have areas which could expand slightly with heat and not impact wear or friction in a negative way.

*IF* they do dig in enough to find out if the rumors are true, I'm primarily suspecting various coated surfaces within the actual combustion chamber area and/or the TJI/HCCI prechamber areas, primarily the nozzles. Piston crowns, valve faces, and the various prechamber components could expand without impacting tolerances beyond what is desired to raise compression ratio.

*IF* the rumors have merit, it would take expansion that would decrease the chamber area of each cylinder by a bit less that one cubic centimeter. With a large bore as well as large valves there is a decent bit of surface area to play with, and it might be possible.




It will be interesting to see what comes out of the FIA meeting, but I have a feeling that it might end up like the Ferrari engine saga. Clarifications and changes forced, but nothing ever proven that the public gets to see.

[Nitrodaze]

I suspect that *IF* we ever find out that the rumors are true, the metals that expand will be used in very limited areas. As you say, all metals expand with temperature, but for the most important areas this has been factored in so that the engine is at it's best under full operating temperature. As such bores, pistons, rods, valves, bearings would likely not change over how they were designed. Otherwise it would probably result in either increased engine wear or excess friction.

BUT we have areas which could expand slightly with heat and not impact wear or friction in a negative way.

*IF* they do dig in enough to find out if the rumors are true, I'm primarily suspecting various coated surfaces within the actual combustion chamber area and/or the TJI/HCCI prechamber areas, primarily the nozzles. Piston crowns, valve faces, and the various prechamber components could expand without impacting tolerances beyond what is desired to raise compression ratio.

*IF* the rumors have merit, it would take expansion that would decrease the chamber area of each cylinder by a bit less that one cubic centimeter. With a large bore as well as large valves there is a decent bit of surface area to play with, and it might be possible.




It will be interesting to see what comes out of the FIA meeting, but I have a feeling that it might end up like the Ferrari engine saga. Clarifications and changes forced, but nothing ever proven that the public gets to see.

If they have found a loophole, it would most probably be in the design of the conrod. They may have designed the conrod to stretch under temperature to increase the compression from 16:01 to 18:1. The Aluminium block and bore may be the same as from the previous engine. Of course, this is pure speculation; we would never know what trickery they may have used. Whatever it is, it is quite ingenious.

[Steve Boyd]

The swept volume limit is 1600 cc, so 266.7 cc per cylinder.

For a 16:1 compression ratio the combustion volume is therefore 17.78 cc.

For the compression to increase to 18:1 the combustion chamber needs to reduce to 15.69 cc, a reduction of just over 2 cc.

If we take the bore of the engine to be 80 mm (as indicated by the "2014-2025 engine technical specifications" on this page https://en.wikipedia.org/wiki/Formula_One_engines) then expanding the length of the conrod and piston crown height by 0.4 mm would do the trick.

Sounds simple but the crankcase and cylinder head also expand so you've got to get the rod+piston crown height to expand by 0.4 mm more than the expansion of the crankcase+head. The problem here is that aluminium alloys, typically used in crankcases expand by roughly twice as much as the steels typically used in conrods for the same temperature rise. It might actually be easier to use an alloy steel for the crankcase and reduce that expansion rather than try to increase the expansion of the rod+piston.

[Nitrodaze]

The swept volume limit is 1600 cc, so 266.7 cc per cylinder.

For a 16:1 compression ratio the combustion volume is therefore 17.78 cc.

For the compression to increase to 18:1 the combustion chamber needs to reduce to 15.69 cc, a reduction of just over 2 cc.

If we take the bore of the engine to be 80 mm (as indicated by the "2014-2025 engine technical specifications" on this page https://en.wikipedia.org/wiki/Formula_One_engines) then expanding the length of the conrod and piston crown height by 0.4 mm would do the trick.

Sounds simple but the crankcase and cylinder head also expand so you've got to get the rod+piston crown height to expand by 0.4 mm more than the expansion of the crankcase+head. The problem here is that aluminium alloys, typically used in crankcases expand by roughly twice as much as the steels typically used in conrods for the same temperature rise. It might actually be easier to use an alloy steel for the crankcase and reduce that expansion rather than try to increase the expansion of the rod+piston.

I hear Ferrari has gone down the route of a steel crankcase. Even so, they are apparently revising the design of the engine to adopt the Mercedes approach. I think there is more to it than meet the eyes.

[Steve Boyd]

I think there is more to it than meet the eyes.
I think you're right, but will we ever find out the truth?

The other factor is that if you try to do anything fancy with the pistons it has to withstand huge forces and if you don't get that right it's going to ruin your reliability.

It also could be a huge bluff forcing other teams to use part of their cost-cap chasing wild geese.

[airshifter]

I think you're right, but will we ever find out the truth?

The other factor is that if you try to do anything fancy with the pistons it has to withstand huge forces and if you don't get that right it's going to ruin your reliability.

It also could be a huge bluff forcing other teams to use part of their cost-cap chasing wild geese.

I wondered about the bluff angle as well. Get in the other teams heads early in the game!

But IF it's real, I doubt we will ever get the full details. Only time will tell, but if either team builds a strong engine it should help with tissue sales until it's all sorted out.

[Steve Boyd]

In the news thread @Fortitude posted:


Mattia Binotto just told Ferrari why they are already doomed in 2026 battle with Mercedes
21 January 2026
David Comerford
F1 Oversteer

It has been reported that Ferrari could protest the results of the Australian Grand Prix, the first round of the season. They feel Mercedes are breaking the spirit of the rules. However, speaking to The Race, Audi boss Mattia Binotto questioned whether this approach is viable, because they can’t pinpoint exactly which feature of the car is illegal. “You can protest if you know what you’re protesting,” Binotto, the former Ferrari team principal, said.

F1 teams will meet to discuss the issue on Thursday, but Binotto says this won’t lead to a ban. Instead, Audi are pushing for the introduction of a real-time measuring device, but this would take time. “I don’t think there will be clarity or compromise,” he said. “The meeting, which has been set for the 22nd of January, is more to continue to discuss how can we improve or develop a methodology for the future to measure the compression ratios in operating conditions.”

‘Can’t pinpoint exactly which feature of the car is illegal’;

https://www.f1oversteer.com/news/mattia-binotto-just-told-ferrari-why-they-are-already-doomed-in-2026-battle-with-mercedes/

The bit that says Audi want real time monitoring of compression ratio is interesting. Compression ratio isn't a pressusre ratio, its a volume ratio. To monitor it in real time at 12000 rpm would need a volume measurement at the bottom of the stroke and another at the top of the stroke 2.5 milliseconds apart. You could monitor cylinder pressure continuously but correlating that with compression ratio is virtually impossible. The rule as written is clear and easily enforcible and in my opinion should be left as it is. As engine parts expand in use the compression ratio is bound to change, and that change will be different for different engine designs. the only way to make it the same for everybody would be to mandate a single engine and then it wouldn't be F1.

[Nitrodaze]

In the news thread @Fortitude posted:


The bit that says Audi want real time monitoring of compression ratio is interesting. Compression ratio isn't a pressusre ratio, its a volume ratio. To monitor it in real time at 12000 rpm would need a volume measurement at the bottom of the stroke and another at the top of the stroke 2.5 milliseconds apart. You could monitor cylinder pressure continuously but correlating that with compression ratio is virtually impossible. The rule as written is clear and easily enforcible and in my opinion should be left as it is. As engine parts expand in use the compression ratio is bound to change, and that change will be different for different engine designs. the only way to make it the same for everybody would be to mandate a single engine and then it wouldn't be F1.

That would be full circle to Observer Effect. Putting monitoring devices in the engine would complicate engine design and possibly introduce more failure points in the engine. It is a difficult one to prove either way.

Ferrari going with a steel cylinder sleeve means it would not take advantage of the expansion trick and may be short by a few horsepower as a consequence. To be fair, the Ferrari approach is the ideal way to design an engine to comply strictly with the regulations. Steel ensures that the engine complies with the 1:16 compression ratio at all temperatures.

That said, the 1:18 expansion trick may not be a good idea in the long run. It may make the engine brittle, especially at those high-temperature tracks. A risky new concept like this one is bound to have lots of teething problems as they work out the best way to cool it or keep it at its optimum operating temperatures at various track conditions. Also, if they turn out to be miles ahead of everyone in the first three races, chances are the paddock may revolt.

From a reliability perspective, it may even out over the season. It would probably be down mostly to the drivers. I worry for Mercedes as they struggled for years to have a car that was solid in all temperature situations. This trick may produce a continuation of that trend. If they can find a solution to ensure the engine is in its optimal temperature in all conditions, then we may be set for a repeat of Alonso vs Hamilton with Russell and Antonelli. That is a mouth-watering proposition. It would be astonishing if the young Italian can win his first F1 championship in his second year. He would be the youngest champion in F1 history l think.

But l doubt it, the experienced head of Russell may win out. Whatever the case, chances are we may be set for another new world champion this season.

[Nitrodaze]

These 2026 engines seem to sound louder than past hybrid engines. Big sound is back.

[Steve Boyd]

Sounds simple but the crankcase and cylinder head also expand so you've got to get the rod+piston crown height to expand by 0.4 mm more than the expansion of the crankcase+head. The problem here is that aluminium alloys, typically used in crankcases expand by roughly twice as much as the steels typically used in conrods for the same temperature rise. It might actually be easier to use an alloy steel for the crankcase and reduce that expansion rather than try to increase the expansion of the rod+piston.
I've had an even better idea!
You make the crakshaft out of something that expands a lot. That'll give you more compression plus it'll increase the stroke so the capacity goes up as well. Double whammy!

[Nitrodaze]

I've had an even better idea!
You make the crakshaft out of something that expands a lot. That'll give you more compression plus it'll increase the stroke so the capacity goes up as well. Double whammy!

The engine block would need to expand as well, or you may get knocking. But l see how a well-designed crank assembly could produce the desired effect.

[Nitrodaze]

It seems the FIA have agreed to testing engine compression at high temperatures from the Australian GP. If Mercedes is doing what everyone is saying, they might be cooked. Once again, the championship is wide open. I bet Russell is kicking something hard.

[F1nKS]

Wolff is kind of annoyed


“I don’t understand why some teams are so focused on everyone else and keep arguing about something that’s already clear and transparent,” Wolff said. “Communication with the FIA has been positive. The procedure is standard. So sort out your own crap — don’t hold secret meetings to invent ways to check parts that don’t even exist yet.”

[Nitrodaze]

Wolff is kind of annoyed

If Mercedes turns out to be cooked, who is the likely new favourite? Ferrari is lighter than the Mercedes W17 at the mo. McLaren has weight problems as well. Aston Martin has not shown their hand properly, so we do not know if the new chassis works well with the Honda engine.

From a fuel perspective, Shell seems ahead of the other fuel suppliers, as they have been supplying racing biofuels for some time now. Which may suggest that Ferrari might have the edge to be the favourite.

That said, we have to keep an eye out for Redbull.

[F1nKS]

If Mercedes turns out to be cooked, who is the likely new favourite? Ferrari is lighter than the Mercedes W17 at the mo. McLaren has weight problems as well. Aston Martin has not shown their hand properly, so we do not know if the new chassis works well with the Honda engine.

From a fuel perspective, Shell seems ahead of the other fuel suppliers, as they have been supplying racing biofuels for some time now. Which may suggest that Ferrari might have the edge to be the favourite.

That said, we have to keep an eye out for Redbull.

In baseball, Spring training is the season of hope. Every fanbase can talk themselves into believing this is finally their year.

After the official practice session, at least we will be able to identify the pretenders.

[Nitrodaze]

In baseball, Spring training is the season of hope. Every fanbase can talk themselves into believing this is finally their year.

After the official practice session, at least we will be able to identify the pretenders.

True, but seriously, I am for innovation. I hope the FIA leave Mercedes alone. All the other teams are scared even before the cars are driven in anger. Teams are scared is no reason to change rules or come up with new tests or monitoring.

I think they should all go racing and let the best team that has done a better job win it all.

[Steve Boyd]

It seems the FIA have agreed to testing engine compression at high temperatures from the Australian GP.I'd love to see how they propose to do that.

[Nitrodaze]

The shakedown testing of Barcelona has whetted our appetites for F1 racing to resume. While the test showed that Mercedes has the edge over the rest of the grid, Ferrari's pace suggested that there might be more to what we saw than meets the eye.

The Bahrain test is where the cars would be driven in anger. The driver would be exploring the limits of their car to determine if they have the car under them that gives them a realistic chance of fighting for the driver's title this season.

The pecking order, as it were, shall be exposed by the end of the Bahrain test. And the stark reality of the prospect of each team shall dawn upon them as they head to Melbourne for the Australian GP.

I hope for a change; it is closer than previous seasons. One thing is certain: it would be vicious in the midfield. Racing Bull and Haas are well primed. Williams and Alpine would definitely be challenged strongly. It is unclear where Aston Martin would be located in all of this. But it would not be surprising of the usual order of things is shaken up somewhat.


Check out this article to read more : The 2026 Renaissance (https://medium.com/motor-racing/2026-f1s-season-of-renaissance-a90da482eb7a)