Why Carlos Sainz’s Williams F1 transfer matters to Mercedes most of all

Thumbnail for article regarding possible Sainz Williams contract — Photo: © IMAGO

Carlos Sainz

Why Carlos Sainz’s Williams F1 transfer matters to Mercedes most of all

The Spaniard's move could tell us something very interesting about 2026 onwards

Daniel Austin

Monday 29 July 2024 18:04 Updated: 22:14

Having been blindsided by Ferrari’s surprise snaring of Lewis Hamilton for 2025 onwards, Carlos Sainz has spent the past few months combining his standard Formula 1 racing schedule with grafting away in the paddock alongside his entourage to secure his long-term future.

After months of links to and talks with teams including Red Bull, Mercedes, and Audi, Sainz has finally confirmed where he will race beyond the end of 2024 by signing a multi-year agreement with Williams.

F1 HEADLINES: Sainz OFFICIALLY confirms new team as Perez question comes to an end

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Team principal James Vowles has succeeded with a significant coup by securing the services of the three-time race winner, who was forced to accept that dropping lower down the grid was inevitable once Red Bull extended Sergio Perez's contract and Mercedes informed him that their priority lies with highly-rated teenager Andrea Kimi Antonelli.

Where do Williams stand?

Despite Williams’ poor results over recent years – they have finished last in the constructors’ standings four times since 2018, ending the season no higher than seventh in that time – there are reasons for Sainz to be optimistic about his future with the Grove-based squad.

Since joining from Mercedes in time for the start of the 2023 campaign, Vowles has made significant behind-the-scenes changes at Williams, from reconfiguring key personnel and supercharging sponsorships to altering outdated systems and pushing past backmarker rivals on track in a short space of time.

Even with those positives in mind, though, Sainz will know deep down that he is taking a significant step backwards in his career. At 29, that is far from ideal.

James Vowles has shaken things up at Williams since his arrival from Mercedes

With 2025 being the final season in which the current engine and aerodynamic regulations will remain the same, the running order on track is unlikely to change very much at all. Sainz will be well aware of this, and so will understand that the best he can likely hope for next season are sporadic appearances in the final round of qualifying and a smattering of points finishes.

But from 2026, the whole game changes. The simultaneous ripping up of both engine and aero regulations means F1 will undergo one of its biggest changes in decades. There is no telling which team will handle that revolution best.

That doesn’t mean however that those on the inside of F1 can’t make well-educated guesses. The engine manufacturers who will design the next generation of power units – Red Bull Powertrains/Ford, Ferrari, Mercedes, Renault, Honda, and Audi – have all been hard at work on the project for years at this stage and whispers about their progress will have been heard.

Given Sainz’s final choice essentially boiled down to Audi and Williams, his decision to opt for the latter is intriguing.

Why did Sainz not choose Audi?

For a long time, Sainz seemed almost certain to end up at Audi. The Volkswagen-owned brand is putting a huge amount of resources into its push into the top tier of motorsport, and his former team principal Andreas Seidl was due to be running the project, but has now been replaced by another former boss of Sainz's - former Ferrari chief Mattia Binotto.

The links don't stop there - the Spaniard's father Carlos Sainz Sr. has been associated with Volkswagen for many years, having recently become the oldest Dakar Rally winner this year driving for Audi.

Still, Sainz Jr. opted instead for Williams, a non-works outfit with far less money and, in theory at least, less potential than Audi.

Perhaps, then, Sainz’s decision can be read as a huge endorsement of the power unit which Williams will run in F1’s new era – Mercedes’.

Carlos Sainz had been tipped to make the move to Audi

What does the move mean for Mercedes?

The Silver Arrows’ works team has toiled since the current regulations were implemented in 2022, dropping away from frontrunners Red Bull into a midfield outfit which competes for the podium places but has seldom challenged for race wins and has not been in contention for championship titles.

The slump has been deep enough for Hamilton to be tempted away, his confidence that the team could rediscover the peak of its powers clearly having evaporated during the two seasons he has spent labouring to mediocre finishes in the middle of the pack. With a recent flurry of winning form, however, there is some debate over whether Hamilton may go on to regret the move.

Sainz is now putting his future largely in Mercedes' hands. If they can nail the regulation change, their customer teams McLaren and Williams will benefit hugely too. If they cannot, neither team will have a chance of competing high up the field.

Toto Wolff and Mercedes will be hoping for much better things from 2026 onwards

It would make sense for Sainz to back the Mercedes power unit over Audi’s version. When F1’s power units last underwent a huge revamp in 2014, it was Mercedes who delivered the best rendition, completely outstripping their rivals and powering themselves into domination of an entire generation.

In comparison, Audi are not just an unknown but completely inexperienced, and are undergoing turmoil at the top of their hierarchy as their entry to the championship draws nearer.

If Sainz has made the right bet, then his partnership with Williams could prove very fruitful indeed.

Perhaps more importantly, though, Mercedes could catapult themselves back to the front of the field full-time after years spent on the back foot.

Red Bull Lewis Hamilton Ferrari Mercedes Formula 1 Carlos Sainz