Some sport utility vehicles, small vans and pickups are susceptible to on-road rollover under certain conditions. These vehicles' tires produce forces that support them, allow them to brake and maneuver, and in this case, to roll them over. We therefore examine the properties of tires that may aid or hinder a vehicle rolling over. To do this, we first introduce a quantity called the stability margin based on the difference between static stability factor and tire friction coefficient. The sensitivity of the stability margin to changes in its parameters is derived. This is used to examine how properties of tires may affect roll-over resistance. Properties of tires, such as coefficient of friction, overturning moment, camber dependence, load dependence, size, and pressure are examined in relation to rollover. Examples are given. Practical suggestions for selecting tires for vehicles with low static stability factors are given. Suggestions are made for tire construction that would maximize rollover resistance, but maintain the utility of the tire.