I couldnt find a good answer by searching. Anyway, I have a set of 17X7.5s with a 40mm offset, and I was thinking of running 215/45/R17s all around. Does this sound like it will work? I am worried about the 7.5" wide rim withthe 40mm offset. Thanks guys.

 

The only potential snag is rubbing the front spring - you'll have to just slap it on there. Tire brands vary in sidewall shape.

I had 17x7.5 +35mm offset w/ 215/45's on my n/a with RB and Intrax springs b4 I sold it and had no problems at all.

 

If it were to snag, is it possible/wise to run a 5mm spacer in there to push it out a bit?

 

Yes, but I don't like spacers. When I got my TII I started with some 18x8 +40mm offset with 235/35/18 and needed to run 3mm spacers to clear the front springs. (Keep in mind I have Ground Control coilovers using 2.5" diameter Eibach ERS springs)
I always had a slight shimmy. (they weren't exactly hubcentric, some generic looking thing from America's Tire)
As soon as I switched tires to 225/40/18 I was able to ditch the spacers and BARELY clear the front springs. Now the car runs like driving on glass in comparison.

 

So your ground control/eibach spring setup: Are they larger or smaller in diameter than stock?

 

These springs are 2.5" at the top and the bottom - they do not taper so it gives you more room for a bit wider wheel.

 

I have 215/45 Dunlop SP8000s on 17*7.5 +42 wheels with no rubing problems at all. You have the correct offset for an FC. My wheels sit 2mm closer to the spring than yours, so everything is good for you.

Greg