Was told that 215/50/17 should only go on a 7.5 wide rim?I ran that type of set-up on my 99cx , one size smaller than spec for summer and one size larger for winter. Your acceleration will be quicker off the line but your top end will suffer. Something else of concern will be breaking, your breaks will try to lock up faster causing your ABS to kick in sooner! It's recommended that you don't exceed 3% of OEM.
I thought the factory rims were + 45 offset?I believe the OEM rim is 7x17 +35os, your new rim is 8x17 +40os. This will move your rim out to fender 8mm and in to suspension 18mm. Your tire width changes .8" between these two tires and will move tread out to fender 5mm and in to suspension 15mm.