Abstract
Vehicle dynamics primarily depends on a tire force and its direction acting on each wheel. Each tire capability is determined by its vertical load and adhesion condition. So if a vehicle dimensions, acceleration condition, and a tire adhesion condition are given, the turning ability of a vehicle would be calculated considering weight transfer among each wheel, using the concept of a tire friction circle. Thus, the dynamic limit of a vehicle, say, maximum acceleration and turning ability, is expressed by squares of iso-maximum-lateral acceleration, together with a steer property. Those squares, hereinafter called "dynamic square", are useful to consider effects of height of gravitational center, weight distribution, and various driving models. In addition, this method enables the analysis of additional yawing moment to a vehicle by tire forces.