I've brought some 16" Zetec S alloys that im going to fit winter tyres to and swap them over with my 17" wheels in the winter.

My car is the 1.0 ecoboost version

What tyre size can i fit as in the manual it states -

195/45/r16 - 1.0 ecoboost

195/50/r16 - all engines except 1.2 + 1.4 duratec and 1.6

Im guessing i can fit either tyre size according to the manual?

Having check the tyres sizes on a tyre size converter/calculator to compare to my 205/40/r17 the differences are

195/45/r16 = -2.35%

195/50/r16 = +0.84%

I'm thinking i would be better off with the 195/50 as they are closer one im swapping over with, but the zetec s 16"s usually come with 195/45 so im unsure what to do?

Mine are 17" Zetec S wheels and they have 205/40's on them, 195, 45 would still work though

Its the 16" wheels i am fitting the tyres to, my 17" are 205/40 aswell

With 16's the standard size is usally 195/45 but going up to 50 or down to 40 would be fine depending on how think or thick you want the tyres to look Etc