currently have 15 inch alloys on 195 and 50 wall tyres. i am wondering if i drop the wall to 45 will this stop any rubbing i have been getting

Depends on width offset and lowering. Should most definetly help though!

they are just going back on the same. no lowering kit no off set. myn only rub on full compression of the spring like a bump or something

No offset? All wheels have an offset mate

But if they only rub somtimes then yes 45 profile should definetly help.

lol my bad well they will be a factory offset nothing which i have ajusted

You need to give more info for a proper answer. Like car, suspention height, wheel size, offset and where it rubs etc.

If it is rubbng the side it may or may not help by reducing the profile.