Mercedes didn’t spend the last two seasons watching McLaren turn its engines into trophies just to play nice now that 2026 has reset the chessboard.
That, essentially, is the subtext behind Martin Brundle’s comments at the Barcelona shakedown: if he were running Mercedes, he’d be giving McLaren power unit information “as late as they can get away with”. Not because there’s anything illegal or underhand in that on its own — but because in a year where details decide winners, timing is a detail.
McLaren arrive as the team to beat on paper, having taken the Constructors’ crown in both 2024 and 2025, and with Lando Norris adding the Drivers’ title in 2025 as the Woking squad won 14 of 24 races. Mercedes, meanwhile, have had to sit in boardrooms and explain why a customer team has been partying with their silverware. Brundle’s point was blunt: Toto Wolff won’t have enjoyed that one bit.
And in 2026, the sport has handed Mercedes a chance to tilt the playing field back towards the supplier. The new rules have moved F1 away from the ground-effect era and back towards over-body aero concepts, with active aerodynamics in the mix via moveable front and rear wings. That’s a clean-sheet moment for the chassis departments — and it’s why the paddock mood has shifted from last year’s “who can copy the best idea fastest?” to “who’s actually got the best idea?”
But there’s another layer that’s less visible and arguably more decisive early on: packaging around the power unit.
McLaren and Mercedes will both run the same Mercedes power unit this season — and the regulations are explicit about what that means. Appendix 4, 1.4 of the power unit rules states each manufacturer submits a single homologation dossier applying to all competitors it supplies, and that units must be identical to the dossier, run identical control software, and be capable of being operated in precisely the same way. In other words, Mercedes can’t simply hand McLaren a “version B” and call it competition.
Yet that doesn’t make the relationship symmetrical.
Mercedes are the works team. They’ve designed the engine and the car in tandem, with “advanced knowledge of pretty much everything on that power unit” as Brundle put it, developed and run in simulation for months. McLaren, by definition, are integrating someone else’s product into their concept — waiting for the key dimensions, cooling demands, installation requirements and the rest of the unglamorous stuff that ultimately shapes the bodywork, the weight distribution, and how aggressive you can be with the aero.
That’s where Brundle’s “late as they can get away with” line lands. It’s not about withholding the engine itself. It’s about information flow — and, specifically, the advantage you get when your chassis team isn’t reacting to a supplier’s finalised decisions but influencing them, or at least knowing them early enough that compromises don’t metastasise into pace loss.
“Can you imagine when Toto goes into a board meeting at Mercedes HQ, and they mention that McLaren, their customer team, has won the last two world championships,” Brundle said in Barcelona. He painted the 2025 picture in stark terms too: McLaren “absolutely dominated it with nearly twice as many points as the next runner”.
For Wolff, whose competitive instincts are hardly a paddock secret, this season is more than a regulation change. It’s an opportunity to reassert what being a works team is supposed to buy you.
Brundle also acknowledged the guardrails. The rules, he said, are “very tightly controlled” to prevent customer teams being short-changed. That’s true — but the sport can regulate hardware equality more easily than it can regulate the natural advantages of having built the thing in the first place. In an era where installation is performance, the works team will always have a head start on how to make the whole car behave as a single organism.
The knock-on is that this could get political quickly, even if nobody calls it that. McLaren will push for clarity early because their design needs stability — late changes to PU installation can force messy rework and compromise aero surfaces that were supposed to be clean and efficient. Mercedes, if they’re being ruthless within the rules, will guard every day of lead time they can keep for themselves.
Brundle didn’t pretend otherwise. “I’m sure they only tell McLaren what they have to tell them as late as they can get away with,” he said. “I would if I was them.”
There’s also a sharper edge to this rivalry than in the usual supplier-customer story. Mercedes aren’t supplying an underdog grateful to be in the fight; they’re supplying the reigning champions. They’re supplying the team that just used Mercedes power to beat Mercedes. Twice. In that context, the relationship stops being cosy and starts being transactional — a contract enforced by regulations, not camaraderie.
And Brundle’s closing observation is telling too: if Mercedes can’t win with their own car, they’d rather it be “another team with their power unit.” That’s not just an aside — it’s the sort of thinking that can seep into how hard you fight a customer rival on the margins.
If the 2026 cars really have brought everyone closer — as the early mood suggests, with the new aero rules wiping away the legacy advantages of the last cycle — then Mercedes vs McLaren won’t just be about which team interpreted the active aero better. It’ll be about who managed the grey areas of a shared power unit era more cleverly: the champions trying to stay champions while bolting in someone else’s heart, and the manufacturer trying to make sure its own factory team gets to enjoy the glory that used to come as standard with building the engine.
