I was running 17x7 with +40 offset which should be fine, however, sometimes it is not the rim but the tyre. I was running 235/50 rubber (to give some sidewall flexing and improve ride) and they rubbed very slightly on front plastic liners. It is a simple calculation to compare how much closer to the centre of the car a particular rim/tyre combo is would be.
Assuming you go +45 then simplistically that is 5mm closer to centre of car than I was running so your tyres would need to be 10mm narrower (225). someone can please check my logic but if std offset is +46 then your issue is likely not the rim but the rubber...
---------- Post added at 12:37 PM ---------- 6 hour anti-bump limit - Previous post was at 12:34 PM ----------
Actually, I forgot the rim width was 8" so your rim would be 17mm closer (not 5mm)
The bit about tyres still stands (i think)