Because of its available axle torque and geometric configuration, the usual farm tractor is not a particularly stable vehicle. In view of the increasing emphasis being placed on safety and comfort, a knowledge of the degree of stability to be expected from a tractor under various conditions of dynamic loading might be an aid in designing safer and more functional tractors. One method of attaining this knowledge would be the use of a mathematical model. The advantages offered by a mathematical model over prototype testing include greater speed, lower costs, and, more importantly, the ability to perform preliminary evaluation of proposed designs.