Tech chief Adrian Newey has tipped Honda to deliver a 'good step' in 2016 that could help McLaren overhaul his own Red Bull Formula 1 team.
After Red Bull failed in its efforts to land Mercedes, Ferrari or Honda engines for next year, Newey says his outfit is braced for a tough time as it relies on Renault to make progress with its power unit.
Despite some optimism about there being more to come from Red Bull's chassis, Newey is well aware that it will be too much to expect Renault to deliver a big leap forwards.
That is why he fears progress being made by its rivals in 2016, especially McLaren, which he expects to exploit improvements from engine partner Honda.
"I think it is going to be an extremely difficult season for us frankly," Newey told Motorsport.com during a visit to the most recent MRF championship event in Dubai.
"If we start the engine with the same power as we have had throughout 2014 and 2015, which I think may well be the case, then we are going to be even further behind.
"According to our own research we found some reasonable gains on the chassis side, but the works teams will of course all move forward. Mercedes and Ferrari will move forwards."
"Toro Rosso, our sister team by having a 2015 Ferrari, will be considerably ahead of this year's Renault power unit.
"I believe Honda, what we have seen, will make a good step. I think their internal combustion engine is a reasonable engine.
"Their problem this year has been that they made the recovery units on the turbo, the MGU-H, far too small. But that is an easy problem to address over the winter.
"So, next year's going to be very difficult for us. It's really down to, I think, what happens next with the sport, for 2017 and beyond.
"Is there desire from the governing body to allow private teams such as ourselves to properly have competitive engines or not?"
Interview by Darshan Chokhani