McLaren team principal Andrea Stella has stated that whilst a decision to continue its engine partnership with Mercedes was “simple” and “straightforward”, it is not the final piece in the jigsaw for a championship challenge.

McLaren returned to Mercedes power in 2021 after six difficult seasons with Honda and then Renault for three years apiece.

This past year, except for the season-opening race in Bahrain, the MCL60s of Lando Norris and Oscar Piastri were blessed with reliability on the power unit front.

Despite the options on the table when new PU regulations start in 2026, including a reunion with Honda, or switching to Red Bull Powertrains or Audi, McLaren opted to keep faith with Mercedes by signing a five-year extension to its existing agreement from that season.

One of the key components of the deal is that McLaren will have input into the development of the system, and crucially, how it will be integrated into its car for that year.

Explaining the reasoning behind the team’s decision, Stella said: “It was quite straightforward because we are very happy with the ongoing collaboration. They were absolutely instrumental in the progress of the team this year.

“Above all, the reassurance we got from a technical point of view, the operational standards, the solidity of what we saw when we checked what was at stake for 2026, made the decision quite simple for us.

“We are just delighted we have this level of continuity and stability as we look forward.”

Stella appreciates, however, that there is more to being a title challenger than simply possessing a strong power unit.

McLaren’s progress this year was staggering after upgrades were fitted to the car in Austria and Singapore, with the expectation now of an upward curve toward the next major rules upheaval in 2026.

For Stella, a reliable engine is “one of the elements you need”, adding: “It’s a necessary condition, but not sufficient at all.

“To contend for championships, there’s quite a lot of work needs to be done on the chassis side.

“I think we will be competitive for the years to come from the power unit side, that’s for sure. That’s why we made this decision, but there’s so much work to do on the chassis.

“Even this year, what we have achieved, yes, it’s important – remarkable in a certain way – but we didn’t develop the car for a few races, and we saw some of the (other) cars brought some upgrades, and immediately our competitiveness was not as good as it was a few races previously.

“It’s an incredibly competitive business. So, for us, it’s a focus, certainly in the collaboration with HPP but above all, on ourselves and making sure this momentum is carried forward into the next years.”