Zak Brown has moved to swat away the more dramatic whispers doing the rounds in the paddock ahead of the 2026 opener, insisting he “can’t imagine” a Melbourne grid missing any Mercedes-powered cars even as rivals push for a late tweak to how the new power units are policed.
The backdrop is an increasingly familiar pre-season ritual: a fresh rules cycle, a technical grey area, and a political scramble over whether it’s clever interpretation or something that needs tightening up before anyone scores points.
Over the winter, reports have suggested two manufacturers — widely named as Mercedes and Red Bull Powertrains — have found a way to exploit a quirk in the 2026 engine regulations around compression ratios. Under the new rules, compression ratios must not exceed 16.0, down from 18.0 previously. The controversy, as it’s been framed, is that compression ratios are measured when the engine is cold, and that this has opened the door to an approach that could allow a higher effective ratio once the car is running on track.
If true, it’s the kind of marginal gain that isn’t marginal at all in a new formula: a potential performance and efficiency bump, and the sort of thing that can shape the pecking order before it’s even properly established.
That’s precisely why some of the other manufacturers are said to be pressing for a rule change in time for the Australian Grand Prix on March 8 — whether through on-track sensors or a measurement protocol applied when the power unit is at operating temperature in the garage. The immediate fear, at least in the more breathless versions of the story, is that a late change could have knock-on effects for those already committed to a design path.
Brown, though, sounded unimpressed by the idea that this ends with Mercedes customer teams staring at an empty pitlane in Melbourne. McLaren have been a Mercedes customer since 2021, and in 2026 are joined on that power unit by Williams and Alpine, alongside the works Mercedes team. That’s eight cars — a sizeable chunk of a 22-car grid — and not the sort of number Formula 1 can casually afford to have mired in uncertainty.
“I can’t imagine that you wouldn’t have Mercedes teams on the grid in Australia,” Brown said when asked about the prospect.
He also made it clear McLaren aren’t in the room when the key technical arguments are being thrashed out — an important detail in itself, because it underlines where the real leverage sits. Customer teams care deeply about what’s decided, but they don’t get a vote in the power unit politics.
“We’re not privy to those conversations and so I wouldn’t even know from a power unit point of view what would be required to change the regulations,” he said. “But we’ll have all the Mercedes teams on the grid in Australia, I’m sure.”
Behind the scenes, the FIA and manufacturers have already held a string of meetings aimed at getting ahead of the issue before it mutates into an ugly start to a new era. Technical experts representing the engine manufacturers met on January 22, just days before the first 2026 test began in Barcelona. Another technical meeting followed last week, ahead of a session of the Power Unit Advisory Committee (PUAC).
The governance here matters. Any significant and immediate change requires the backing of four of the five manufacturers, plus the FIA and FOM. In other words, this isn’t a case of one unhappy party complaining loudly enough and forcing a rewrite — it needs a broad coalition.
That’s where the paddock intrigue sharpens. Red Bull Powertrains’ stance could be pivotal amid suggestions it may not have extracted the same benefit as Mercedes from the alleged loophole. If that’s the case, the incentives shift: today’s defender of the status quo can become tomorrow’s advocate for “clarification”, especially when the competitive stakes are this high.
Brown, for his part, framed the whole saga as the usual game of narrative and pressure that plays out whenever someone appears to have landed on a strong solution early. His line is straightforward: if it’s within the written regulations, it’s legitimate — and the objections are just rivals doing their job.
“It’s typical politics of Formula 1,” he said. “The engine has been designed and totally compliant within the rules. That’s what the sport is about.
“[This case is] no different to 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 the reality is the engine is completely compliant, passed all its tests, and I think HPP has done a good job.”
There’s a telling subtext in Brown’s comments too: McLaren may be one of the teams with the most to lose if Mercedes is forced into a redesign or revalidation process, but it’s also not McLaren’s fight to lead. Brown said the team is being kept informed by Mercedes High Performance Powertrains, yet isn’t part of the technical working group discussions where any formal change would be shaped.
“We’re aware, but it’s a Mercedes topic,” he added. “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.”
The broader point is that this is exactly how new regulations begin to bite: not just on track, but in committee rooms, with “interpretation” and “intent” weaponised depending on who’s ahead. The FIA’s challenge is to police the line between smart engineering and an outcome that undermines what the 2026 rules were meant to achieve — without moving the goalposts so late that it becomes a credibility problem of its own.
For now, Brown’s message is simple: don’t expect a crisis at Albert Park. Whether the rest of the paddock is ready to let it go that easily is another matter.
