McLaren CEO Zak Brown has defended Mercedes amid the growing controversy around F1’s 2026 engine regulations. The debate has intensified weeks ahead of the new season, with rival teams questioning whether a potential compression-ratio loophole could provide an early advantage. Brown insisted that the Mercedes power unit is legal and dismissed claims of a major performance gain.
The controversy centers on the new 2026 regulations, which reduce the maximum compression ratio from 18:1 to 16:1. The measurement is taken at ambient and static conditions. Rival manufacturers believe Mercedes and Red Bull designed internal components that expand at operating temperatures, effectively going over the compression limit while still passing checks. Early reports suggest that the loophole could be worth upto several tenths per lap.
As the situation developed, multiple manufacturers raised concerns with the FIA. Ferrari, Honda, and Audi pushed for clarification and possible changes to the measurement process before the season begins. Red Bull has also joined them after reportedly failing to implement the changes. FIA has held technical meetings and clarified that they want the issue resolved before the Australian Grand Prix.
Amid the scrutiny, Zak Brown publicly backed Mercedes and rejected the idea of any rule-breaking.
“The engine has been designed and totally compliant within the rules. That’s what the sport is about, no different than things like double diffusers that we’ve seen in the past where they’re compliant within the rules. I don’t believe there’s a significant advantage as being represented by the competition, but of course their job is any perceived advantage, they’ll make some story out of it. But reality is the engine is completely compliant, passed all its tests and I think HPP has done a good job,” he told The Race.
Mercedes is entering the longest engine production cycle of the hybrid era, supplying power units to its own works team as well as McLaren, Williams, and Alpine. They had a standout Barcelona Shakedown that has only added to those rumors.
Brown also clarified McLaren’s position in the debate, explaining that the team does not build the power unit and therefore is not involved in the technical discussions around the regulations.
“It’s a Mercedes topic. We obviously don’t build and design the power unit. So HPP does a good job of keeping us in the loop because obviously we’re very interested, but we don’t sit in the power unit working group where those conversations happen… I can’t imagine that you wouldn’t have Mercedes teams on the grid in Australia,” he added.
The FIA continues working toward finalizing measurement protocols at Bahrain, with further discussions expected following recent meetings, as the sport aims to prevent legal disputes once the season begins.
Zak Brown and Andrea Stella praise Red Bull-Ford power unit performance amid Mercedes’ engine row
While defending Mercedes, Zak Brown also highlighted the early performance of Red Bull’s new engine partner during pre-season running. The Red Bull-Ford power unit drew attention at the Barcelona shakedown despite not headlining the lap time.
Max Verstappen was the fastest RBPT, who finished seventh on the timesheets and over a second behind Ferrari’s benchmark lap. However, teams treated the times cautiously, focusing on mileage and reliability during the early running. Brown pointed to both factors when discussing what stood out from the test.
“The Red Bull-Ford engine seems very, very strong, so hats off to them. Not only did it seem to be very quick, but also very reliable. The reliability in general seemed to be very strong for very sophisticated, new, immature regulations that will develop over time. The amount of running everyone got in was impressive,” he added (via The Race).
McLaren’s own preparation has also progressed positively. The team completed 287 laps during its shakedown after a delayed debut for the new car. Early running was briefly limited by a fuel issue, but Lando Norris and Oscar Piastri completed their programs without any reliability concerns. Norris ended the five-day test as the third-fastest driver with a best lap of 1m16.594s.
Edited by Parag Jain
