Why McLaren won't have Mercedes' new power unit for F1 British Grand Prix

Zak Brown says the decision is related to the mileage on McLaren's current power units, although he expects the team to receive Mercedes' reliability upgrade for the F1 Belgian Grand Prix

While Audi and Ferrari introduced their first ADUO upgrades of the season in Barcelona and Spielberg respectively, Mercedes also arrived in Austria with a new power unit specification.

In Mercedes' case, however, it was not an ADUO step but a reliability upgrade following the numerous retirements earlier this season, with Kimi Antonelli's DNF in Barcelona being the most recent example for the works team.

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Most Mercedes customer teams are running the new power unit this weekend. Ahead of the sole practice session at Silverstone, Alpine drivers Pierre Gasly and Franco Colapinto both switched to new components, including a fresh internal combustion engine and turbocharger.

Carlos Sainz also changed to a completely new power unit following his problems in Austria, although his Williams team-mate Alex Albon is still running the unit used at Spielberg.

That means McLaren is the only Mercedes customer team not running the new power unit specification with either driver at the British Grand Prix, as Brown confirmed during Friday's FIA press conference.

"We need to get the current Mercedes engine. We're the only one without the new engine, which will be coming for us shortly," the McLaren CEO said.

"Of course, we'd like to have it. Anytime you have performance that you know is coming, but you don't have it on your car yet, you want to get it as quickly as possible.

"But I wouldn't say it's a frustration. It is just what it is. We just keep our head down and keep pushing hard. It'll be in the back [of our cars] in not too long."

Lando Norris with McLaren's special livery at Silverstone

Photo by: Simon Galloway / LAT Images via Getty Images

That inevitably brings back memories of the start of the season, when McLaren explained that it was experiencing the downsides of being a customer for the first time ever, particularly in terms of information transfer and a different learning curve than the Mercedes works team.

This situation, however, is completely different. Brown clarified that it is related to the mileage on the existing engines and that McLaren has not yet reached the point where an engine change is needed.

"You've got to cycle through your engines and we've got life left on our current engines, so we need to wait until we do an engine change.

"Williams got theirs because Carlos had his issue, so he needed an engine change. I don't recall exactly Alpine's scenario, but I think they've got two of them as well, so it's just a timing sequence thing."

Looking at the mileage covered so far during the 2026 F1 season, Alpine has indeed completed the highest mileage of all the Mercedes customer teams by some margin, partly due to the number of retirements McLaren has suffered.

Williams sits lower on that list, which also explains why Albon has not yet switched to the new specification either.

If McLaren adds significant mileage at Silverstone, Brown expects Lando Norris and Oscar Piastri to switch to the new specification ahead of the next race weekend in Belgium.

McLaren expects to get Mercedes' reliability upgrade ahead of the next race weekend at Spa

Photo by: Sam Bagnall / Sutton Images via Getty Images

"You'd want it as quickly as you can, but you need to run cycles through the engines. Obviously you can move things in and out, but we'll have it soon, hopefully for the next race."

Spa-Francorchamps is one of the most power-sensitive circuits on the calendar, making an engine change ahead of the Belgian Grand Prix a logical moment.

Mercedes team principal Toto Wolff already explained in Austria that fitting a fresh power unit generally brings a small performance benefit, as several horsepower are typically lost over the life cycle of an engine.

Aside from the power unit specification itself, McLaren team principal Andrea Stella has said that around 30% of the team's time loss to Mercedes is actually on the straights.

McLaren is currently investigating that deficit further, although Stella openly acknowledged that a significant part of it comes down to drag.