can i fit +30 offset wheels on the FC without problems?

More than likely it will rub depending on the width of the wheels.

depends on how wide of a tire you are getting but it's getting close, Max front would be a 225 tire (235 if you have coilovers w 2.5" OD springs). Rear you can go to 255 tire I think on a +30

its 17x8.5 and the tire width is 245. i was thinking to myself that the offset is too low (because stock is like +38 or 40 right?) and i'd have to run spacers.

no.. low is good... low moves the wheel out. but regardless I doubt you can run a 245 tire on the front. That is too wide if you don't roll your fenders, or have flares

this offset stuff is confusig. anyone have a chart or something showing which part of the wheel affects offset? its the mounting point to the centerline, correct?

I'm running 18" X 8" with a +40 offset, 225 40's and eibach springs, I have a solid 1/4" of clearance where the top of the tire is closest to the springs.



The link below is one intertpretation of offset and backspace, I hope it can shead some light on the subject.



link

thanks 89rag

http://www.rsracing.com/tech-wheel.html



I think 17x8.5 on a + 30 mm offset is still a little close for comfort, it would depend on the size of tire you are running and the manufacturer of the tire to be certain it doesn't run anywhere.