Although it’s not a steadfast rule, many off-roaders choose a rim size that’s no more than half of their tire size. So if you’re running on stock 30-inch tires, don’t go bigger than a 15-inch wheel. Same goes for 16-inch rims on 33s or 17-inch rims on 35s. The reason for this is that you still have sufficient sidewall, your tires won’t rub on the vehicle, and you can still maximize your off-roading power.