McLaren-Honda racing director Eric Boullier says the British team is “ready to win” whereas its Japanese engine partner “may not be”.
Honda endured a dismal return to F1 in 2015 and while it greatly improved its troublesome power unit last year, McLaren still remained some way off the front-running pace.
New executive director Zak Brown recently ruled out fighting for victory in 2017, calling next season a more realistic timeframe.
Speaking to Spanish publication MARCA at a recent Pirelli event held in Turin, Boullier’s comments will hardly allay fears of another winless campaign for the fabled Woking team.
“McLaren is ready to win, but Honda may not be,” the Frenchman said.
“The engines are already approaching the end of their evolution and there will be a time when they will not be able to use more fuel, but [Honda] have a considerable distance to go.
“We know that we will find more performance, but the biggest risk is that we don't know if we can reach that potential this year.”
Honda’s head of F1 project Yusuke Hasegawa previously admitted that the Japanese engine supplier has taken an agressive “high risk” approach on the design of its 2017-spec power plant.
McLaren's last win stretches back to Jenson Button's victory at the 2012 Brazilian Grand Prix.