Formula 1’s 2026 season hasn’t even started and already the gloves are off.

McLaren team principal Zak Brown has lodged a formal complaint with the FIA accusing Red Bull of exploiting a major loophole in the new power unit regulations with the RB22 engine – a move that could hand Max Verstappen and the reigning world champions an unfair advantage right from the season-opening Australian Grand Prix.

The complaint, confirmed by the FIA late yesterday, centres on the internal combustion engine compression ratio. The 2026 rules cap the static compression ratio at 16:1 (down from 18:1 in previous years), a limit that can only be verified during cold, static tests. Both Red Bull and Mercedes are fully compliant in these bench tests.

However, Brown’s submission – backed by telemetry data, flow visualisation images and independent simulations – alleges that under race conditions, when engines reach peak operating temperatures, the RB22 achieves a higher effective compression ratio through thermal expansion. The claimed gain: up to 0.3 seconds per lap in qualifying and race trim.

In a statement released by McLaren this morning, Brown did not mince words:

“We believe there is clear evidence of a performance advantage that falls outside the spirit and letter of the 2026 regulations. This is not about sour grapes – it’s about protecting the integrity of the championship before the lights go out in Melbourne. The FIA must act decisively and transparently.”

The FIA responded swiftly, confirming an immediate technical investigation:

“Following receipt of a formal protest from McLaren, the FIA has opened a review into the compression ratio behaviour of certain power units under dynamic, high-temperature conditions. A technical working group has been convened with all power unit manufacturers. An update will be provided in due course.”

Racing Bulls team principal Laurent Mekies – whose team runs identical Red Bull-Ford power units – reacted with visible anger during a hastily arranged media session in Melbourne:

“This is ridiculous. The car passed every homologation test, every static check, every scrutineering procedure. To come after us now, days before the first race, with accusations based on speculation and not hard evidence, is nothing short of sabotage. If they have proof, show it. If not, let us race.”

The timing is brutal. Pre-season testing in Barcelona showed Red Bull and Mercedes comfortably quickest in both dry and wet conditions, with the RB22’s tiny sidepod inlets already raising eyebrows. Now, just weeks before the season opener at Albert Park, the engine row threatens to overshadow everything.

Insiders say the alleged loophole exploits thermal expansion tolerances: as the engine heats up, components expand slightly, pushing the real-world compression ratio beyond 16:1 while still passing cold static tests. The gain – 0.3 seconds per lap – would be transformative in a season where power unit development is frozen from 2026 onward.

Mercedes team principal Toto Wolff, whose own engine is under similar scrutiny, issued a defiant response:

“We have been in constant dialogue with the FIA. Everything we do is within the regulations as written. If rivals want to spend their time inventing conspiracies instead of developing their cars, that’s their choice. We’ll be ready in Melbourne.”

The paddock is divided. Ferrari, Aston Martin and Alpine are watching closely – any penalty against Red Bull or Mercedes could reshape the entire pecking order. McLaren insists this is about fairness, not revenge: Lando Norris and Oscar Piastri won the 2025 titles, but the team fears losing the advantage if rivals exploit grey areas.

F1 CEO Stefano Domenicali has remained silent so far, but sources say he is “extremely concerned” about the optics: a season reset meant to level the field is already mired in controversy before the first practice session.

The FIA’s technical working group is expected to report back before the Melbourne weekend. Until then, the 2026 title fight is being waged not on track – but in technical hearings and press rooms.

One thing is already clear: the new era begins with suspicion, not celebration.

Red Bull’s RB22 engine is under fire. McLaren has fired the first shot. And Laurent Mekies is ready to fight back.

The Australian Grand Prix just became must-watch television – for all the wrong reasons.