Several F1 teams fear that Mercedes and Red Bull Powertrains have found a way to bring the compression ratio closer to 18:1 while driving, while still staying within the rules in the static test.
The 2026 engine rules require a compression ratio of 16:1, compared to 18:1 last year. This ratio is always measured at ambient temperature, when the engine is not running. As a result, any expansion of materials due to heat when the car is actually driving on the track is not taken into account. The higher ratio leads to more power and so the competition fears that an unfair advantage will be gained.
“We have to trust that the FIA is making the right decisions here,” said Audi’s technical director James Key during the presentation of the team’s 2026 car. “These are new rules. There must be a level playing field. If someone comes up with a smart diffuser and you say that it is not actually allowed, but that person can use it for the rest of the year while others are not allowed to, then that is not correct. We would never accept that.”
Mercedes does not understand commotion
However, Mercedes remains adamant that its engines fully comply with the rules as set out, and looks with some surprise at the actions of some competitors – reportedly including Honda – who object to this.
Mercedes is rumored to have found an engine trick, but Wolff emphasizes the legality of the power source.
Photo by: Mercedes AMG
“I just don’t understand why some teams focus more on others and keep discussing something that is very clear and transparent,” Mercedes team boss Toto Wolff told a select group of media, including Motorsport.comduring the official presentation of the 2026 Mercedes W17. “The communication with the FIA has always been very positive, and that applies not only to the compression ratio, but also to other matters.”
“Specifically on this point, it is crystal clear what the regulations say. It is also clear what the standard procedures are for engines, even outside Formula 1. So: just get your act together,” Wolff appeals to his rivals. “The power source is legal. The engine complies with how the regulations are written. And the power source complies with how the checks are carried out.”
Entertain with distraction
Although no immediate changes are expected for the time being, alternative ways to measure the compression ratio are still being discussed, for example by also carrying out checks under driving conditions. Any proposals would have to go through the usual procedures, including a meeting of the F1 Power Unit Advisory Committee and then a vote within the F1 Commission. However, Wolff is unimpressed by attempts to change testing procedures on what he believes is industry standard.
Wolff states that the other teams need to get their “business in order” instead of focusing on Mercedes.
Photo by: Mercedes AMG
“Having secret meetings, sending secret letters and always coming up with new ways to test that don’t actually exist… I can at least say on our behalf that we try to minimize distractions and mainly look at ourselves, rather than at others. After all, it is quite clear what the rules say and also what the FIA has said to us and to them so far,” said Wolff.
“But maybe we’re all different. Maybe you want to find excuses before you even start as to why things aren’t going well. If someone wants to entertain themselves with distractions, everyone is free to do so.”
The FIA has made it clear that it wants to fully resolve the issue before the start of the season in Australia next month, so that the issue does not continue to simmer into the new season and the focus can be on racing on track.
“We absolutely want to avoid these types of controversies and ensure that when people go racing, everyone understands the rules in exactly the same way,” FIA single-seater director Nikolas Tombazis told reporters. Motorsport.com during the recent Autosport Business Exchange. “It is inevitable that certain issues will arise with such a new set of regulations, and we feel it is our responsibility to resolve them before the first race.”
We want your opinion!
What would you like to see on Motorsport.com?
Take our 5-minute survey.
– The Motorsport.com team
Worth a look
