bit of a random question....if they do use 2017 engines where would those 2017 PUs be coming from?
given how many units Mclaren went through plus the late season timing of their breakup, i cant imagine there are a lot of fresh/unused PU left over...unless they over produced them or would they be using refurbished/rebuilt units if the 2017 PU gets called back into service.
also a thought about the 3 engine limit for 2018...no doubt there will be a lot of races where penalties are incurred so this may be a moot point but given the 3 engine allotment , Honda wont have many opportunities to introduce new upgrades with out receiving even more penalties.
how this impacts their development cycle for 2018 will be interesting to say the least.