Formula 1 Australian GP
FIA announces clampdown on compression ratio tests from June 2026
Formula 1 constructors and the FIA have reached a compromise to quell the compression ratio saga that has dominated the 2026 pre-season
Filip Cleeren
Edited: Feb 28, 2026, 10:26 AM
Copy link
Share on Viber
Andrea Kimi Antonelli, Mercedes
Photo by: Simon Galloway / LAT Images via Getty Images
Formula 1's governing body the FIA says the series' power unit manufacturers have unanimously approved changes to how engine compression ratios are measured, with revisions coming as early as 1 June.
The compression ratio of the V6 combustion engines, which measures how much the air-fuel mixture inside a cylinder can be compressed, has been reduced to 16:1 for this generation of power units - partly to help make building engines more accessible to newcomers like Audi.
But rival manufacturers, believed to be led by Audi, took issue with a clever way to comply with the 16:1 compression ratio in cold and static conditions, which is how it is measured by the FIA, while expanding it under hot, running conditions and gaining a significant advantage. Audi was joined by Honda and Ferrari in lobbying the FIA to address the issue before the start of the 2026 season next week in Australia as it was rumoured that Mercedes had used the trick to its advantage - even though the team received reassurances its power units are fully legal.
F1's manufacturers disagreed over their interpretation of the 2026 power unit regulations
Photo by: Kym Illman / Getty Images
Following a series of discussions, the FIA put up a compromise for an e-vote among the five power unit manufacturers, which also includes Red Bull-Ford, giving all parties 10 days to vote for the proposal. That solution is to start measuring the engine compression ratios both in hot and cold conditions from 1 June, and subsequently only measuring them in operating conditions at 130C from the 2027 season onwards. The FIA has now said all manufacturers have voted for the proposal, with the changes also ratified by the FIA World Motor Sport Council.
"A significant effort has been invested in finding a solution to the topic of the compression ratio," the FIA said in a statement on Saturday morning. "This parameter, which was one of the key fundamental targets of these regulations in order to attract newcomers to the sport, is limited in the regulations to 16:1, measured in cold conditions.
"The FIA has worked to find a compromise solution which determines that the compression ratio will be controlled in both hot and cold conditions from 1 June 2026, and subsequently only in the operating conditions (130deg C) from 2027 onwards."
The revised article C5.4.3 of the 2026 technical regulations now states the following:
"No cylinder, as referred to by C5.1.3, of the Engine may have a geometric compression ratio higher than 16.0, measured in the following conditions:
• Until 31 May 2026: when the Engine is at ambient temperature
• From 1 June 2026 to 31 December 2026: when the Engine is at ambient temperature as well as when the Engine is at 130degC.
Any component, assembly, mechanism, or integrated arrangement of components that is designed or functions to increase the compression ratio in operating conditions beyond 16.0 is prohibited."
"Tell us what we’re allowed to do, and the rest matters little" - Red Bull
Speaking exclusively to Motorsport.com, Red Bull team principal Laurent Mekies said his squad, which is producing its own power units for the first time in 2026, just wanted clarity on the matter before going into the new campaign.
“We’re asking for clarity. Tell us what we’re allowed to do, and the rest matters little: it’s essential to have a clear understanding of what is permitted, and then I believe every competitor should be free to reach the result by following the path they consider best. This applies not only to the power unit, but to everything," Mekies said.
The FIA also said it will continue evaluation data from pre-season testing and the first rounds of the season amid concerns over the draconian energy harvesting tactics drivers will have to use to optimise the new-for-2026 power units, which rely much more heavily on electric power than their predecessors.
"The regulations introduced for 2026 represent one of the biggest changes in recent memory," the statement continued. "All parties acknowledge that with the introduction of such significant regulatory changes, there are collective learnings to be taken from pre-season testing and the initial rounds of the 2026 championship.
"Further evaluation and technical checks on energy management matters are ongoing."
Read Also:
Formula 1Toto Wolff: F1 compression ratio drama "a storm in a teacup"
Formula 1Compression ratio saga "typical politics of F1", says McLaren's Zak Brown
Formula 1Mercedes and Red Bull under scrutiny over F1 2026 engine compression ratio
We want your opinion!
What would you like to see on Motorsport.com?
Take our 5 minute survey.
- The Motorsport.com Team
Read and post comments
Read also :
Share Or Save This Story
Copy link
Share on Viber
Previous article Mercedes F1 unveils new adidas 2026 Silver Arrows collection
Next article F1 scraps mandatory Monaco GP two-stop rule for 2026
Top Comments
There are no comments at the moment. Would you like to write one?
View More & Comment
More from
Filip Cleeren
McLaren held fresh talks after Singapore GP clash as Lando Norris promises to "make better decisions"
Formula 1
Formula 1
United States GP
McLaren held fresh talks after Singapore GP clash as Lando Norris promises to "make better decisions"
Inside the competition building F1’s future engineering talent
Formula 1
Formula 1
United States GP
Inside the competition building F1’s future engineering talent
Latest news
Tim Clark wants NASCAR to be better storytellers to counter "brand perception problem"
NASCAR Cup
NAS NASCAR Cup 55 min
Tim Clark wants NASCAR to be better storytellers to counter "brand perception problem"
Why NASCAR's Zane Smith fine for Carson Hocevar contact was consistent
NASCAR Cup
NAS NASCAR Cup
Talladega II
1 h
Why NASCAR's Zane Smith fine for Carson Hocevar contact was consistent
Jimmie Johnson on the NASCAR business world: "It's a war"
NASCAR Cup
NAS NASCAR Cup 1 h
Jimmie Johnson on the NASCAR business world: "It's a war"
David Alonso lashes out at Dani Holgado: "When you’re not a good person, there’s nothing you can do"
Moto2
MOT2 Moto2
Phillip Island
1 h
David Alonso lashes out at Dani Holgado: "When you’re not a good person, there’s nothing you can do"
Feature
Discover prime content
Subscribe and access Motorsport.com with your ad-blocker.
From Formula 1 to MotoGP we report straight from the paddock because we love our sport, just like you. In order to keep delivering our expert journalism, our website uses advertising. Still, we want to give you the opportunity to enjoy an ad-free and tracker-free website and to continue using your adblocker.
You have 2 options:
- Become a subscriber.
- Disable your adblocker.
Subscribe now Already subscribed? Sign in here
Already disabled your adblocker?
Reload page
Manage Alerts
Subscribe