FIA issues bombshell verdict in Mercedes-Red Bull 'loophole' saga for the new V6 power unit: Reports

Mercedes and Red Bull have been involved in the 2026 power unit controversy, with the FIA having to intervene in the same. The two teams found a loophole in the power unit regulations, which was reported over a week ago. The latest reports suggest that FIA has issued a verdict on the loophole and will allow the two teams to continue using the controversial V6 power unit.

FIA introduced major regulation changes for the 2026 F1 season with new powerunits, chassis, and aerodynamics. Compared to the previous engine, the MGU-H was removed, and the output from the hybrid was increased. However, the loophole exploited by Mercedes and Red Bull was the compression ratio.

According to the regulations, the compression ratio was reduced to 16:1 for 2026, and the test for compression would take place at ambient temperature. The reports suggested that Mercedes and Red Bull used material that expands as the engine heats up, and increases the compression ratio to 18:1, while still passing the compression tests.

Formula 1 Testing in Abu Dhabi - Source: Getty

The rivals, including Honda, Audi, and Ferrari, reportedly asked FIA to step in as they wanted clarification around the same. According to Motorsport.it, FIA has given its verdict on Mercedes and Red Bull’s loophole saga and allowed both teams to continue with the V6 power unit.

“Mercedes and Red Bull Powertrains can proceed on their own terms. The FIA has admitted that the combustion chambers of their respective engines are legal if, during tests carried out at room temperature, a compression ratio of 16:1 is measured. It doesn't matter if, when heated, the resulting value is higher,” read the report.

With a little over a month until the first over-season test, Mercedes and Red Bull would've had to start from scratch if the FIA rules against them. The Brackley-based outfit had also reportedly kept FIA in the loop regarding the engine development.

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How can the rivals respond to the FIA’s green light to Mercedes and Red Bull's power unit?

Mercedes was reportedly the first team to come up with a compression ratio loophole, followed by Red Bull. The Milton Keynes-based outfit reportedly learnt about the compression ratio loophole after a bunch of Mercedes employees joined the team. It is believed that Mercedes has got the power unit sorted out while Red Bull is still a few steps behind.

With a month until the first winter test, and over two months before the first race, rivals including Honda, Audi, and Ferrari still have the opportunity to exploit the loophole. While the reports came out only a week ago, the rivals reportedly had an idea aboutthe Mercedes compression ratio loophole months ago.

The rival teams can also lodge a formal complaint to the Stewards at the first race of the season. If there is a 2% gap between the power units, FIA will allow for the Additional Development and Upgrade Opportunities (ADUO) after the first six races of the season.

Edited by Pranay Bhagi