The FIA has confirmed a mid-season adjustment to the regulations following a dispute regarding Formula 1 engines, introducing a new test effective from June.
As preparations intensify for the upcoming 2026 season, which kicks off in Melbourne next weekend, concerns have arisen over possible loopholes. Mercedes has drawn attention after other teams alleged they have circumvented restrictions on engine compression ratios.
In a substantial overhaul of regulations, the compression ratio limit has been reduced from 18.0 to 16.0, but current measurements are taken while the engine is not at full temperature. Other teams believe Mercedes is exploiting this, potentially giving them an edge in performance.
In response, the FIA announced that starting June 1, measurements will be conducted at an engine ambient temperature of 130 degrees. Seven races will occur before this test is implemented, with 17 races on the calendar from June onwards.
The FIA stated, “Certain aspects of these revisions received unanimous approval from all Formula 1 power unit manufacturers,” which include Mercedes, Ferrari, Red Bull-Ford, Audi, and Honda. The proposed modifications are a response to insights gained from pre-season testing and feedback from drivers and teams.
The FIA added, “Considerable effort has been devoted to resolving the compression ratio issue, which was central to these regulations aimed at attracting new entrants. The ratio is capped at 16:1 under cold conditions.” From June 1, 2026, this measure will be applied in both hot and cold conditions, with operations set to align to the 130deg C threshold from 2027 onward.
Mercedes team principal Toto Wolff noted prior to the pre-season tests that changing the power unit regulations could negatively impact performance. However, following the Bahrain test, he indicated Mercedes would feel “pretty comfortable” even if another team protested their engine at the Australian Grand Prix, a scenario now less likely given the resolution reached.
