The new F1 season begins in Melbourne next weekend and the build up has seen controversy as rival teams claimed Mercedes have found a way around engine compression ratio limits. The compression ratio limit has been lowered from 18.0 under the previous ruleset to 16.0 as part of F1’s biggest regulation changes ever.

The FIA has announced a new test will take place from June 1, ensuring the ratio is tested when the engine ambient temperature is at 130 degrees.

F1’s engine manufacturers,Mercedes, Ferrari, Red Bull-Ford, Audi and Honda, unanimously approved ‘some aspects of the amendments’ according to the FIA.

“The modifications to the technical regulations follow the pre-season tests in Barcelona and Bahrain and extensive feedback received from drivers and teams,” said the FIA.

“A significant effort has been invested in finding a solution to the topic of the compression ratio. 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 June 1 2026, and subsequently only in the operating conditions (130deg C) from 2027 onwards.

“The regulations introduced for 2026 represent one of the biggest changes in recent memory. 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.”

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Mercedes team principal Toto Wolff stated before F1’s pre-season tests in Bahrain that a change to regulations could be “quite damaging for the performance”. His stance softened and Wolff then claimed Mercedes would be “pretty comfortable” if a team protested their engine.

“We said it all along that this looks like a storm in a teacup, the whole thing, and numbers were coming up that were… if these numbers would have been true, I absolutely understand why somebody would fight it, but eventually, it’s not worth the fight,” he said.

“It doesn’t change anything for us, whether we stay like this or whether we change to the new regulations, and that’s been a process. But we also want to be good citizens in the sport because it doesn’t make a big difference we then changed opinion.”

Mercedes will have seven races before needing to ensure they abide by the latest rule change.