Owners manuel states towing cap. with 18" wheels is 500lbs less than 17" wheels. So I can gain 500lbs on t.v.w.r. just by swapping wheels, Go Figure.
David

 

That assumes you stay with the same size tires as OE. It's not wheels, it is the final tire diameter that can be ordered from the factory. If your 17" wheel/tire combo are the same size as the OE 18" wheel/tire combo, you still lose the 500lbs.