I'm running the 19" coupe wheels (8's up front 8.5's in back) with stock tire sizes. I didnt get any rubbing with stock tires but did with Kumho's on the rear (245/40/19). A different tread design would have prevented rubbing. I just rolled my fenders (pinched the inside lip in) and the rubbing was gone.

 

Can I threadjack and ask why the X's cannot stagger if they are using the same tires? Why would width matter, is it a weight thing?