Williams have said that the team will make a decision on their Formula 1 engine supplier this year, ahead of the regulation changes set for 2026.
So far there are six power unit manufacturers that have registered, including Honda, Red Bull Ford and Audi.
Williams have used Mercedes power units since the start of the hybrid era in 2014 but they are deciding whether to continue this partnership from 2026, according to Team Principal James Vowles.
"We're happy with the relationship that's been in place for many years, Mercedes have fundamentally produced the best on average power unit across certainly the last 15 years," he told media, including RacingNews365.com.
"Where we are at the moment, certainly with Mercedes and other OEMs [original equipment manufacturers], is reviewing. Because we have to ensure we review the marketplace and we'll make decisions on that shortly.
"For where we are in terms of relationships, so far, Mercedes are doing an incredibly good job."
When asked about the timeframe, Vowles said that a decision would be made during 2023 to move forward with development.
He added: "It has to be this year, for where all teams will move forward. I think you'll struggle to see teams migrate away from their current pattern much beyond this year."
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Pros and cons to being a customer team
Vowles believes the current approach of being a customer team by Williams has its pros and cons, after the last couple of championships have shown the advantages of being a works outfit.
"To win championships, if you look at who's won typically, it's OEMs and you need to be manufacturer-backed in order to do it," Vowles explained.
"And that's the difficult pathway that we have to fight along the way.
"I think for now, we have a realistic target on our shoulders. We know that, step one, with what we have right now we have the ability to move forward from where we are."
He continues to highlight the importance of being "in charge of your own destiny" in F1 as a team.
"At some point, you have to be in charge of your own destiny and you're simply not when you have a reliance on someone else providing," Vowles added.
"A simple example of it is, as good as the components are, you don't know what your aero direction will be until very late. And it's normally dominated by the decision of the manufacturer's circumstance.
"However, we have bigger fish to fry at the moment."
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