What width of rims would i need for 225/45/R17? would 7.5" be good or would I need 8" Also would they fit?

 

This should help: https://www.northamericanmotoring.co...5-45-17-a.html

 

Standard range of rims for this size tire is 7" to 8.5".
7.5" would be a very good choice.
So would 8".
As for "would they fit?", would need to know what vehicle and what offset and what springs.

 

Getting 225-45-17's to fit is the bigger challenge. Plus the wider the rim the wider the tire will expand. The 8" is much better from a handling perspective since you want as much width on the rim as you can get and stay just under the tire width. Team Dynamics has an 8" rim that several folks have used locally with 235-40-17's with just minor rubbing.

I had rubbing with 225-40-17 A6's for autocross on 7" Kosei K1 TS rims and had to push them out with spacers...5mm rear and 10 to 15mm front. The 225-45 height might be the biggest challenge for you. I run 215-45-17's for DDing on 7" rims.

The referenced thread from Minihune has great info.