Mercedes HPP engine customer has placed it on the “backfoot” in the
2026 season. Of the top four teams – Mercedes, Ferrari, McLaren,
and Red Bull – it is only Stella’s McLaren which is not a works
team when it comes to the power unit, and buys in a Mercedes HPP
supply. In 2024 and 2025, McLaren became the first customer team
to win the constructors’ championship in the turbo hybrid era, with
Lando Norris becoming the first customer-team driver to win the
drivers’ title in ’25. However, at the start of F1’s new
regulations with the complex new power units, McLaren’s title
defence has been hampered – through a combination of its own
unreliability and that of Mercedes HPP. In China, both Norris and
Oscar Piastri failed to start following power unit glitches, with
Stella saying around this time that the team needed more
information from HPP to understand how to better extract
performance. Going further, the Italian has detailed how, in his
view, being a customer squad has placed the team on the “backfoot”
for the season. “I’ve said before, like never before, we felt that
being a customer team has put us on the backfoot,” Stella told
media, including RacingNews365. “When I say this, and I want to be
clear here, to avoid any misunderstanding, it’s not because you are
a lower priority for Mercedes HPP, it’s because you have fewer
opportunities to integrate, to stay on the same timeline when it
comes to addressing reliability problems or exploitation of the
power unit from a performance point of view. “When you have some
experiments on the chassis side, you can add to a long run of the
power unit when you are a works team. “There are many reasons why
reliability associated to power unit or taking advantage of being a
works team from a power unit point of view. I “I think these
reliability issues have made it into 2026, where we had such a
large technical regulation change from a power, from a performance
point of view “There are many related to the power unit, but there
are some, like the gearbox problem on Lando’s car in Canada, which
are purely on the McLaren side. “So, I just want to be totally
fair to our unit supplier, with whom we have a fantastic, very
successful relationship, and still the relationship is great. “The
great relationship allows us to review item by item, learn from
each item, and solve it technically, but when you don’t know what’s
coming, it’s not sufficient to simply address item by item. “You
need to review ultimately the depth, the intensity and the
effectiveness of the various meetings, engagement, sharing of
information processes, both from factory to factory, track to
track, track to factory, and so on.”