Hey -- I've been trying to do some searching but I'm not finding the answers I'm looking for. I might be buying a 2015 WRX very soon, and will obviously need some winter tires for it. I'm looking at the routes of just buying tires and using the OEM rims, or buying another set of winter rims. However, I don't understand a ton about how I can check compatibility of different styles of rims. The NASIOC Master Thread of OEM wheel specs doesn't show the same specs as TireRack. TireRack: Size: 17x7.5 Offset: 48mm Bolt Pattern: 5-114 Backspacing: 6.10" NASIOC: Size: 17x8" Offset: +55 Bolt Pattern: 5x114 Wheel Weight: 24.xx pounds (need more accurate weight) OEM-equipped tire size: 235/45-17 How far off of recommended specs can I go and still keep a good fitment? Can I use 16" rims? How important is the offset? I'm assuming bolt pattern is non-negotiable but what about tire size? Can I go down to 215/50/17 tires? After I figure out which of the above specs are correct, should I just stay with those exact specs?
http://www.rimsntires.com/specspro.jsp Check out that site. you can clearly see the difference in tire sizes and how to get close to the same diameter tire on a different sized rim.
You'll be hard pressed to find an aftermarket wheel with the 55 offset. You should be fine with anything from 45-55. (45 or 48 would be the most common, you might even get away with a 35 offset, but I'm not positive on the 2015 fitments) Narrower is almost always better for a winter tire. You should be fine in the 215/50-55/17 range. Speedo may be a tad off but fitment will be fine. Determining you goals with the car are for the summer and budget can determine what to do now for a wheel and tire set up. If you plan on aftermarket wheels for better performance, different tires, etc., then put the winter tires on the stock wheels and problem solved. If you plan on running your stock set up next summer, best bet is to find a cheap set of wheels for your winter tires.
I use www.willtheyfit.com Works a little better than the previous one since you can test whatever size tire on any size wheel. Gives a better visual too.
Well I've learned a lot about tires and rim fitment in the last few days, but ordered a set from TireRack. Sticking with the same tire size and rim width but going to a slightly smaller offset for winter.