Carlos Sainz has revealed one of the key reasons behind going to Williams for a new phase in his F1 career after being replaced by Lewis Hamilton at Ferrari. The Spanish racer revealed that the involvement of Mercedes as an engine supplier to Williams proved to be a game-changing factor in his team choice.
In 2026, F1 will go through a technical regulation reset. Mercedes is expected to be the heavyweight in the new technical era with the most superior engine, as per ongoing chatter in the F1 paddock. Such a positive change in the Silver Arrows' F1 fortunes means that its customer team, Williams will also receive a big boost in performance.
Carlos Sainz talked about this connection in a recent interview with el Partidazo de COPE on YouTube. When questioned if he expects the growing speculation about Mercedes's 2026 superiority to be true, the 31-year-old replied:
"Yes, I have a lot of confidence in the Mercedes engine, and it's also one of the main reasons why I chose Williams for this rule change, because I knew I was going to use the Mercedes engine. Everything I was hearing about the Mercedes engine is positive, and it continues to be so now."
However, Sainz noted that Williams is not the only team procuring power units from Mercedes, which makes him wary of the possibility that the James Vowles-led team might stay in a familiar position in the pecking order.
"But be careful, we mustn't forget that Mercedes will have a Mercedes engine, McLaren will have a Mercedes engine, Alpine will have a Mercedes engine, and Williams will have a Mercede engine. So that's eight Mercedes-powered cars to beat, two of which are clearly superior right now, especially McLaren, right?"
He also said that Aston Martin could be a strong team to beat under the new regs. The Silverstone-based team's 2026 challenger will be the first product with technical mastermind Adrian Newey's significant input.
And as for Ferrari, Carlos Sainz could not rule out his former team being in the mix for podiums and wins.
"Ferrari is going to be there because Ferrari is always there," the four-time Grand Prix winner said.
Williams boss James Vowles reveals Carlos Sainz's 'surprising' quality
Williams Team Principal James Vowles disclosed a 'surprising' story regarding Carlos Sainz and his professionalism and commitment towards the team. The former Mercedes man highlighted how good the Spaniard's technical feedback about their cars is.
In an appearance on F1's beyond the Grid podcast, while speaking about the impact he wants to have at the side and how Sainz has become a part of that vision, Vowles said:
"As to what surprised me with Carlos, (he has a) really good way of working with engineering teams. Very clear, concise feedback that directs us where we need to be. I didn't have to ask him to come into the factory. He came in at 9 a.m. one day. He was already sat with the aero team deep in conversations over 'Exactly at this point to the data, just there, that's where I feel the front wash out, and look around Turn 9, again, that's where I feel it.' Basically, we watched a team of 15 people then break down into that and go, 'I wonder if it's associated with x, y, or z," he said.
Williams had a bittersweet outing in Singapore last weekend. Both racers were disqualified from qualifying following technical inspections and started the race from the back of the grid. However, Carlos Sainz made an impressive jump from 18th to 10th place in the Singapore Grand Prix, while Alex Albon managed a P14.