Red Bull has admitted to taking its new engine design to the "very limit" of Formula 1’s compression ratio rules, but has no doubts it is legal.

A technical row has been bubbling away in recent weeks with rivals suspecting Red Bull and Mercedes have gained an advantage by exploiting regulations regarding a new 16:1 compression ratio limit for 2026.

The suspicion is that both manufacturers have found a way to fully comply with the 16:1 ceiling when the engine is measured at ambient temperatures, but have their engines run with a much higher compression ratio when out on track.

Nobody outside the two organisations knows for sure how it is being achieved, but it could be through the innovative use of the thermal expansion of certain components, which helps push the piston closer to the top of the combustion chamber during its cycle.

One manufacturer source suggested that the benefit from doing this could be as much as 10kW – which is worth around 0.3–0.4 seconds per lap.

In response to a letter sent by Ferrari, Audi and Honda to the FIA seeking clarification over the rules, a meeting between the governing body and all manufacturers has been scheduled for January 22 to discuss things.

However, it is not anticipated that there will be any change to the measurement procedures nor regulations in the short term. This means that any advantage that Mercedes and Red Bull have could be maintained for much of the 2026 campaign.

Speaking ahead of Red Bull’s season launch in Detroit on Thursday night, Red Bull Powertrains’ technical director Ben Hodgkinson reckoned the rules were clear – and that it was logical for everyone to be aggressive when performance was to be gained.

Asked by The Race for his views on the compression ratio situation, Hodgkinson said: “I think there’s some nervousness from various power unit manufacturers that there might be some clever engineering going on in some teams.

“I’m not quite sure how much of it to listen to, to be honest. I’ve been doing this a very long time, and it’s almost just noise. You just have to play your own race, really.

“I know what we’re doing. I’m confident that what we’re doing is legal.

“Of course, we’ve taken it right to the very limit of what the regulations allow. I’d be surprised if everyone hasn’t done that.

“I suspect it’s a lot of noise about nothing. I expect everyone’s going to be sitting at 16. That’s what I really expect.”

The rules for 2026 introduced a 16:1 limit, down from the 18:1 imposed with the previous generation of power units, in a bid to attract new manufacturers, as it is a much easier target to hit.

Hodgkinson thinks it is too conservative though, and says that with gains coming from even tenths of an improvement with the compression ratio, it is obvious that everyone will be pushing to seek advantages.

“From a purely technical point of view, the compression ratio limit is too low,” he said.

“We have the technology to make combustion fast enough that the compression ratio is way too low. We could make 18:1 work with the speed of combustion that we’ve managed to get.

“It means there’s performance in every tenth of a ratio that you can get. So every manufacturer should really be aiming at 15.999, as far as they dare, when it’s measured.”

The right ingredients

That rivals are probing what Red Bull has done says a lot about the seriousness with which others are taking the new Powertrains project.

For Hodgkinson, who was recruited from Mercedes early on to lead the project, what has been put together at Milton Keynes is as good as he thinks it can be.

And although drawing short of making any firm prediction for what can be achieved on track this year, he thinks that Red Bull has everything it needs to succeed in the long term.

“Obviously, I've got a lot of experience in designing F1 engines, and I've been in it since the V10 days, so I know what a good company looks like,” he said.

“I've got the unique opportunity here to try and shape what the perfect power unit manufacturer needed to look like - and Red Bull have been very accommodating in terms of what facilities we've got.

“I'm pretty confident with our facilities. I think the people we've got are amazing. There's something really unique about a group of people that are part of a startup that we've got.

“They're almost like pioneers. The ownership and dedication I can see in every department is just incredible. So I think we've got all the ingredients. 

"But whether it will turn into a Michelin meal, we'll have to see, won't we? We've definitely got all the ingredients.

“I'm confident that we've built the right company and got the right people. But I think confidence is something that somebody who is about to lose will have, so you're not going to get more from me than that.”

Hodgkinson said that it was impossible to make any firm prediction on the relative form right now against everyone else because teams had not yet run on track together.

“You never really know where you are,” he said, when asked about his gut feeling on where Red Bull’s power unit stacked up for the start of the 2026 season.

“I've described it before to some of my team-mates that it's like a 400 metre race. And I use 400 metres, because a 400 metre race is basically like a sprint.

“So it feels like a sprint, but you're doing it in a stadium on your own, with no crowd, in a different country to all of your competitors. All I know is that we're running as fast as we possibly can.”