Abstract
Nonlinear tyre responses with respect to the lateral force, self aligning torque and longitudinal force development must be considered if a more precise vehicle modelling is required. A procedure describing these responses by simple first order differential equations is shown. It is based on the assumption that in every instant there must be equilibrium between the force caused by the tyre deformation and the force corresponding nonlinearily to the response on some kinematic parameter (steady state response on instantaneous slip angle, longitudinal slip, path curvature). Knowledge of the basic tyre constants and of its empirically described characteristics (for example by the "magic formula") is necessary. (A)