Run Some SidewallLow-profile tires may look cool to some people, but the decreased sidewall height not only increases a rim's susceptibility to damage, but can limit traction. If you've ever seen a drag racing slick wrinkle as the vehicle launches, you'll understand how some sidewall flex can help in gaining traction. For an off-road tire, we find a sidewall height of 6 to 12 inches works well. That means running a 17-inch rim with a 40-inch tire, or it may mean running a 15-inch rim with a 33-inch tire. Leave the 20s to the guys with the big gold teeth.