With 185 width you are getting very close to contacting the top of the cross frame on a 4/4.
^^^ We found this out when I tried to fit 185/70's to my new narrow Plus 4. There's a variation between brands on sidewall shape, and the Blockleys didn't clear on 4/4 wires.
So I had to use the Avons, but even so, clearance is maybe 3mm, with a slight side to side variation.
On my previous narrow Plus 4 the Vredesteins fitted Ok at 185/70, so you just need to watch the front frame.
