i want to get new rims for my car. I would like the tire on the back to be 235/45/17 and the fronts to be 215/45/17. What rim size do i need to have these tire sizes fit nice and snug.

 

I ran 17/225/50 on my 88gxl with stock suspension front and back. Having the back tires a few cenameters wider is not worth it. You then can't rotate to front and back.

 

Well a 235 size tire is pretty beefy for an fc.
Fronts should have no problem with a 215/45R17 size tire.
Rim size is very simple, find 2 rims that are 235mm wide and 17 inches tall, and 2 that are 215mm wide and 17 inches tall.
The 45 wont make a difference, its just the percentage of your width as your sidewall.
Worst case, roll your fenders or throw on a wide body kit.

 

It really depends on what your definition of snug is. A 17*7.5 F and 17*8.5 R would fit snug, but so would a 17*8.5 F and 17*9.5 R. This also depends on your offset.

 

ive got 15s 245/55 in the back and ahm 225/55/15 on the front, stabilizes the car real nice, plus wider in the back is always nice on a RWD, ive still got muscle in my blood

 

That's actually the wrong size for a +1 fitment (versus stock 16" wheels).
225 / 45 / 17 is actually the proper +1 fitment that keeps rolling circumference close to the stock 205 / 55 / 16 size.

235 / 45 / 17 is not an unreasonable size.
Lots of people run a 255 / 40 / 17 in the rears, and the FC can fit tires that wide back there under the stock fenders.
Running a 9.0" at +30 to +40 offset with a 255 / 40 / 17 is just about perfect for the rears.

Fronts are a bit tighter...


-Ted