The Swiss team’s Swedish driver Marcus Ericsson on Thursday said Sauber has been surprised by the disadvantage of using a year-old Ferrari power unit so far in 2017.
But team figures have ruled out a mid-season engine switch.
However, the big rumour in Bahrain is that talks are rapidly progressing with Honda about making the switch for 2018.
But contractually, Honda’s works engine partner McLaren can veto the Japanese marque’s moves to supply customer power to other teams.
“For years, Ron Dennis prevented Honda from working with another team,” a source close to Honda told Speed Week. “But Ron is no longer there.”
However, Sauber is denying that a decision to go with Honda for 2018 is imminent.
“We are negotiating with several manufacturers,” the Hinwil based team said.
A second team for struggling Honda would have several advantages, including doubling the feedback and data about its power unit.
Secondly, it is known that Honda is looking for a route into F1 for its junior drivers Nobuharu Matsushita and Tadasuke Makino.
A source told Speed Week: “There is no room for a Japanese in 2018. But if Tadasuke does a good F3 season, he will do Formula 2 in 2018 and in an ideal world be in F1 by 2019-2020.
“This would also fit with the timing with Pascal Wehrlein, who by 2019 will either go to Mercedes or be pushed to a Mercedes customer team like Williams.”