Red Bull denies switching sides in Mercedes F1 2026 engine row
A peek under the covers of the Red Bull RB22 reveals they’re using an air-to-air cooler arrangement on their powerunit, which is mounted in the saddle position above the powerunit.
Red Bull did not swap sides in the compression ratio saga to leave Mercedes alone; it just followed the process as it wants a “fair” system.
Formula 1’s new engine formula is dominating the headlines in the build-up to the season-opening Australian Grand Prix after Mercedes, and it was initially said Red Bull too, found a loophole in the regulations.
Red Bull denies swapping sides in F1 2026 engine loophole saga
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The loophole relates to the wording of the regulation regarding the compression ratio, which this year has dropped to 16.0. The crux is the word “ambient” in the regulation.
Article C5.4.3 states: “No cylinder of the engine may have a geometric compression ratio higher than 16.0.
“The procedure to measure this value will be detailed by each PU Manufacturer and executed at ambient temperature.
“This procedure must be approved by the FIA Technical Department and included in the PU Manufacturer homologation dossier.”
Mercedes is said to have discovered a way to increase that ratio to 18:0, which still adhering to the geometric compression ratio of 16:0 when the engine is running hot under track conditions.
Early reports suggested that Red Bull-Ford had also identified the loophole.
Rival power unit manufacturers, Ferrari, Audi, and Honda, were said to be unhappy as reports claimed the increase in ratio could be worth as much as four tenths on track.
More on Formula 1’s engine controversy
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Mercedes F1 2026 compression ratio debate nears boiling point ahead of homologation
But as the story progressed, Red Bull seemingly swapped sides, leaving Mercedes alone against the now ‘gang of four’, as some have dubbed the Brackley squad’s rival PUMs.
It is understood the Mercedes HPP engine, which powers Mercedes, McLaren, Williams, and Alpine, faces a crucial supermajority vote when the Power Unit Advisory Committee [PUAC] next meets.
Should Mercedes’ four rival PUMs, the FIA, and FOM agree to a change that PlanetF1.com understands would allow the compression ratio to be measured at hotter temperatures, Mercedes would need to rework its engine ahead of the season-opening Australian GP that begins with FP1 on March 6.
It is a vote that Mercedes could lose as it stands apart from its rival PUMs.
Red Bull, however, insists it didn’t change sides – it just wants a “fair” playing field.
“Now, I think we are just following what the FIA says, to be honest,” Red Bull technical director Pierre Waché told PlanetF1.com and other media at the Bahrain circuit.
“We just vote as a PU manufacturer to what we think should be fair for the system, and after the governance system, we choose what it will be.
“I think I’m not sure we changed our mind.
“We just follow the process on our side. As a newcomer, we just want to be fair with the system and follow all the elements.”
Pressed on whether Red Bull, as has been rumoured, swapped sides because it did “not know quite how to put it into practice”, Waché sidestepped the question.
“I think I don’t know what the others are doing,” said the Frenchman.
“I don’t know what they are doing, seriously. I don’t know if it’s true or not. At the moment, it’s just a rumour.
“And if I was trying to put in place a system that is fair for everybody in the different operations.
“But, yeah, I’m not expert on engines, and I don’t know what they are doing.”
Additional reporting by Thomas Maher
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