Some say " if honda pu will be close to renault in 2018". It's already done in 2017. Maybe it will be same in 2018 but this means Renault developed better than Honda, otherwise Honda will catch or beat. Honda's aim is not Renault but this don't mean they can achieve what they had aimed. I expect all PU will be closer to each other in 2018.
Toro Rosso has better chassis than Sauber and Haas and I expect it will be better next year. So they can beat Williams and Force İndia too if they can do a good job. This season mclaren showed us a chassis good enough can fight mercedes powered williams and FI with current Honda engine. I think Toro Rosso is not far away from mclaren especially first part of season. So they can be a good midpack team with a better season start in terms of chassis and better development rate during the season, with a better Honda PU concentrated only Toro Rosso.
"They [the engines] are completely different," Key told Motorsport.com. "It's a very nicely packaged engine, but the whole power unit is a different architecture.
"It doesn't drop into the same space. There's quite a bit of car layout work that has to be done to adapt to it."
Key says it was important not to waste the aero work that had already been done for 2018.
"We try and stick to a rule that, if a car has already been in a development process for a while, not to upset any major items such as aero surfaces and that sort of thing, so we're not starting from scratch in too many areas.
"We've adapted the car under the skin as best we can. And that's led to quite a different approach to the chassis design, to the way the gearbox works, and so on. We've carried over the concepts and developed them further from this year's car."
The gearbox, which is designed by STR but uses internals from Red Bull Technology, will also be new, and shorter than its predecessor.
"Its layout and its size is different for this engine, compared to what we have this year. I think the concept is the same, but the architecture is different.
"Some internals will carry over, some will be changed, some will be bespoke to the STR box. Otherwise it will be pretty close to what we've been running."
Maybe shorter gearbox will cause shorter car for STH and this may give us a surprise at monaco.