Staying with a 17 inch rim and tire combo is the correct thing to do. OEM direction is more and more a standard 20 inch wheel, which is exactly what you do not want in a off-road vehicle. You get decent air down ability with a 17". Some models out there offer a 18 inch wheel which is probably the limit for practicability when airing down. I like my older 16 inch wheel size, good foot print, and good sidewall protection.