Key factor in Sainz to Williams switch revealed

Williams' long-term commitment to Mercedes and its F1 power units has been signalled as a key factor in Carlos Sainz's decision to join the team by former Aston Martin head of race strategy Bernie Collins.

Williams confirmed earlier this week it had reached a multi-year agreement with Sainz who will join the squad next season.

Sainz had been mulling over his future for several months after being informed by Ferrari early this year he would be replaced in 2025 by seven-time F1 champion Lewis Hamilton.

The Spaniard's commitment takes him into the sport's new era under fresh technical regulations, starting in 2026, with Williams

The Grove-based squad has a long-term partnership in place to run Mercedes' power unit, viewed by some as the strongest in the field.

Collins has suggested the collaboration between the two parties was an important element in Sainz's decision.

“When you look at next year, you can’t see the order of the grid shaking up a lot from where it is this year,” Collins told the Sky F1 podcast.

“You can argue between Williams, Alpine or Audi - Williams is probably the best of those three teams next year anyway.

"Looking further ahead to 2026 with the proposed new regulations that are coming in, that’s going to put much more focus on the engine.”

Collins points to long-term stability

Alpine, who was also chasing Sainz, is set to abandon its engine project and run Mercedes units going forward, although no agreement has been confirmed.

Audi, meanwhile, is an unknown entity as it prepares to enter F1 for the first time in its history.

With Mercedes' history of producing a strong engine at the start of a new regulation cycle, Collins stated Williams offered Sainz the most stable option going forward.

“We don’t know which engine provider Alpine is going to go with," she said. "We know Audi is coming in for the first time in what is currently Sauber.

“We know that Williams will stay with Mercedes. The Mercedes engine, the majority of us consider that is the strongest given what we saw in 2014 with new engine regulations.

“The expectation is, even if it’s not up for podiums, wins or strong points at every race next year, potentially 2026 brings an opportunity.

“That’s maybe only one year of lost results. I think it’s that slightly more forward-sight on Carlos’ behalf, particularly when we don’t have anything written in stone for Alpine in terms of engines.

“That is definitely the riskiest one when looking ahead to 2026.”