Williams chief James Vowles is “reviewing” possible engine suppliers for 2026, though two options appear to be ruled out.
The Grove-based team has been powered by Mercedes since 2014, with their partnership getting ever closer in the years since to include gearboxes and other transferable parts.
Even the arrival of Vowles as Williams team boss from Mercedes earlier this year was seen as a sign of a future commitment between the two.
However, with new power unit regulations coming in three years time, the Briton insists nothing is off the table.
“Clearly, we’re happy with the relationship that’s been in place for many years,” he said. “Mercedes have produced really, fundamentally, the best on-average power unit across certainly the last 15 years.
“Where we are at the moment, certainly with Mercedes and other suppliers is we’re reviewing as we have to.
“We need to ensure we review the marketplace and make decisions on that shortly, about where we are in terms of relationships.
“It [a decision] has to be this year, when all teams will move forward. I think you’ll struggle to see teams migrate away from their current pattern much beyond this year.”
Williams isn’t short of choices when it comes to 2026 with Audi and Red Bull-Ford among the options available.
Previous speculation of a tie-up with Porsche is now gone after it was reported the German manufacturer had dropped its interest in the 2026 regulations.
But as Vowles explained, if Williams is to move forward up the grid, a key part of that is to regain its individuality.
“At some point, you have to be in charge of your own destiny,” he stated, “and you’re simply not when you rely on someone else providing you parts.
“As good as the components are, you don’t know what your aero direction will be until very late. It’s normally dominated by the decision of the manufacturer’s circumstance.
“But to win championships you look at who’s won it – typically it’s a manufacturer, or you need to be manufacturer-backed to do it, you need to have everyone behind you.
“And that’s the difficult pathway that we have to fight along the way.”
One name who could offer Williams that pathway is Honda, with whom they won championships in the 1980s.
The Japanese manufacturer has signalled its intention to continue in F1 for 2026 and beyond but will need a new team as Red Bull sets off with Ford.
Asked about a possible reunion though, Vowles seems unconvinced.
“It’d be hard for me to comment because I’m not sure what [Honda] have facilities-wise,” he said via The Race.
“But I think they’re a little bit further away from where they would need to be to be a serious contender.”