Has anyone had any problems with clearance on 18" wheel and tire combos??

 

This post would be best answered in the Tire and Wheel area.

Also try a search for wheels and rubbing, you should get all the answers you need especially since there is not an easy answer for this question. It depends on your ride height/tire size/wheel offset and width.

 

It's not just the 18" wheels that make the difference. All that other stuff that is critical. If you have the same width, offset as stock and your tire selection is of the aspect ratio to compensate for being 18" so as to keep the correct speedo error, in terms of fitment, you are no different than stock wheels/tires.