Williams team principal James Vowles has played down speculation that Mercedes will have the power unit to beat in 2026.
The 46-year-old insisted the idea was planted by a rival manufacturer in an attempt to make late changes to the regulations.
F1’s power units are undergoing their biggest change since the turbo-hybrid units were first introduced in 2014.
The electrification of the units will be increased, while the MGU-H component has been removed.
Mercedes dominated at the head of the field in 2014 when it produced the most efficient power unit, and paddock speculation has suggested it may be a similar case this time around.
However, Vowles poured cold water over the claims.
“No one knows, no one of any engine manufacturer knows where they’re going to fall out,” Vowles told media including RacingNews365.
“Part of the speculation that appeared was one team and PU manufacturer trying to create a narrative to get some changes, to be completely clear.
“But no one really knows. I strongly doubt Ferrari has done a poor job, they are very good at getting this right year on year.
“Honda this year has produced a benchmark engine. So I don’t think it’s going to be like 2014 where you have such a runaway that you can have all the teams carried with it.
“Mercedes, we’ve been working specifically on 2026 with them since early 2024 when we signed the agreement.
“What I can say is they’ve done good preparation. Let’s see what that translates to.”
Williams, who run Mercedes power units, enter the year looking to improve on its fifth-place result in the standings this year – its best finish since 2017.
However, Vowles conceded that breaching the top three is wishful thinking for the Grove-based squad.
“In terms of our aspirations, top three again would be above what we’re expecting,” Vowles said.
“I’ve made the comment and I mean it – stepping forward year on year is a sensible goal for us.
“Top three would be aspirational.”