Carlos Sainz didn’t pick Williams on a whim. He picked it with 2026 in mind — and with one eye on the star under the engine cover.
The Spaniard, who moved to Grove after Ferrari’s Hamilton-sized reshuffle left him looking for a new home, has been frank about the logic. He wanted a Mercedes power unit for F1’s next big reset. He’s got it. And he’s heard enough about the 2026 spec to feel good about where that could put him.
“Yes, I have a lot of confidence in the Mercedes engine,” Sainz told El Partidazo de COPE. “It’s actually one of the main reasons I chose Williams for this new regulation change. I knew we’d be running the Mercedes power unit, and everything I’ve heard about it has been positive, and still is.”
It’s a gamble with history on its side. The last time F1 tore up the engine rulebook, Mercedes wrote the next chapter — seven straight Drivers’ titles, eight Constructors’ crowns. The 2026 regulations push even further into hybrid territory with a 50/50 split between internal combustion and electric power, a huge increase in battery contribution. If there’s any team you’d back to get on top of that power unit early, it’s the factory in Brixworth.
But Sainz isn’t naïve, and he’s not selling a silver bullet. He knows the PU won’t drive the lap on its own.
“No matter how good the engine is, you still need to get everything right with the chassis,” he said. “That means we have to get everything right with the chassis to stand out.”
That’s the other half of the 2026 story. Alongside the power units, F1’s car rules shrink and slim the machinery, with active aerodynamics and a focus on agility. In other words, the game resets on both axes. Having a strong engine could be necessary but not sufficient, especially when multiple teams will be running the same Mercedes unit.
And the competitive landscape won’t be limited to Mercedes customers. Sainz expects Ferrari to be in the mix — “Ferrari will always be there. Ferrari are always in the fight,” he said — and he’s keeping a close watch on Aston Martin with Honda power, a partnership that has already shown it can deliver when the planets align.
What’s changed in the short term is Williams themselves. This isn’t the team Sainz would’ve joined three years ago. It’s sharper, more confident, and more consistently in the points. Williams sit fifth in the Constructors’ standings, and Sainz has already banked a headline result with his third place in Baku — 15 points that mattered, and a podium that felt like a line in the sand for a project on the up.
“Williams has moved up from ninth to fifth this year, that’s a huge step forward,” he said. “In Formula 1, gaining four positions from one season to the next means you’re doing things right.”
He isn’t promising miracles for 2026’s dress rehearsal either. “Next year, starting to win races might be difficult, but I think we can fight very closely with Ferrari, Mercedes, Red Bull and company.”
That’s Sainz in a nutshell: realistic, but ambitious. He’s bet on a power unit he trusts and a team that’s rediscovered its stride, all while keeping the focus where it matters most — the hard stuff in the wind tunnel and on the shop floor. If Williams nail the chassis and Mercedes deliver the hybrid punch everyone expects, Sainz could be in a very sweet spot when the lights go out on a new era. If not, he’s still backed a team that’s climbing and a manufacturer that usually shows up when regulations get complicated.
Either way, Williams haven’t been this interesting in a long time. And that’s already a win.
