FIA to introduce mid-season F1 engine test after Mercedes loophole row
The FIA has confirmed a mid-season rule change to Formula 1’s power unit regulations, introducing a new test from June to resolve a dispute over engine compression ratios.
Closing the regulation loophole
Rival teams had raised concerns during pre-season testing that Mercedes may have found a way to bypass specific limits within the sport’s extensive 2026 regulation overhaul.
Competitors suggested the Silver Arrows were exploiting a grey area regarding how engine compression is measured when the power unit is not running at full temperature.
Under the new ruleset for the 2026 campaign, the compression ratio limit was lowered from 18.0 to 16.0.
Current protocols only measure this parameter while the engine is cold, a method rivals believed offered the German manufacturer a competitive advantage.
However, the sport’s governing body has now moved to update the technical regulations following the season-opening rounds.
New testing procedures
A new test will be implemented from 1 June, ensuring compliance is checked when the engine ambient temperature is at 130 degrees.
This change will come into force after the seventh race of the season, affecting the remaining 17 rounds of the calendar.
From 2027 onwards, these checks will be conducted exclusively in operating conditions of 130 degrees.
Unanimous manufacturer approval
The FIA stated that “some aspects of the amendments were concurrently approved unanimously” by the sport’s power unit manufacturers.
The grid’s current engine suppliers include Mercedes, Ferrari, Red Bull-Ford, Audi, and Honda.
In a statement, the governing body acknowledged the need for a compromise following extensive feedback from testing in Barcelona and Bahrain.
“A significant effort has been invested in finding a solution to the topic of the compression ratio,” the FIA said.
“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.”
The organization added that further evaluation and technical checks regarding energy management are ongoing.