Toto Wolff reveals costly McLaren regret after Zak Brown left Mercedes boss red-faced

Toto Wolff has revealed that he has some light-hearted regrets about allowing McLaren to become a Mercedes customer team, with Zak Brown's organisation now the dominant force in F1. The Woking squad's recent joy has been underpinned by iron-clad reliability, with neither driver experiencing a power unit failure this season. McLaren have been using Mercedes engines since 2021, following a challenging period using Honda and then Renault power units.

Since then, Brown and team principal Andrea Stella have helped elevate the manufacturer from a struggling brand to an F1 juggernaut. Now, halfway through the 2025 campaign, McLaren are embarrassing the team that supplies their power units. Lando Norris and Oscar Piastri's combined points total is over double that of second-placed Ferrari, with a second successive Constructors' Championship title now all but guaranteed.

Asked about the performance deficit by Sky Italia, Wolff said: "That's also hard for me to explain. Look at where they were three, four years ago, when we signed the deal with them that they were going to use our fast engines for the next few years. Then they were 18th and it was easy to make such a decision.

"With the knowledge of today, I don't know if it was the most intelligent choice in my life to make that deal with them. They have it really well together in terms of engineering, and that's why they perform so insanely well, especially in hot conditions."

McLaren aren't the only rival enjoying the fruits of Mercedes' top-of-the-range power units. Williams have been long-time customers, while Aston Martin are also powered by the Silver Arrows' offering.

For the latest breaking stories and headlines, sign up to our Daily Express F1 newsletter, or join our WhatsApp community here.

That partnership will end with the start of the new regulations in 2026, though, with Aston Martin entering an exclusive partnership with Honda. However, Wolff will still have a four-team stable running Mercedes engines, with Alpine becoming a customer team after ditching their in-house power unit programme.

While this comes with a significant financial incentive for Mercedes, Wolff will be desperate to close the performance gap to his customer team. The Austrian will be pleased to see the back of the ground effect era after a frustrating four years since the 2021 title decider.

Before the new regulations come into play, Wolff has an uncomfortable decision to make regarding his driver line-up. Should he manage to lure Max Verstappen away from rivals Red Bull, he will have the perfect weapon with which he can wrestle back control from McLaren.