This paper presents a computationally efficient tire model developed for real-time simulation that produces functionally correct behavior over a wide variety of operating conditions. The fidelity must be sufficient to support validation of antilock brakes, traction control and chassis control systems.The model is based on an idealized physical representation of the tire. It decomposes the tire-road characteristics into a point model of the contact patch, coupled to the wheel through radial, longitudinal, and lateral stiffness and damping. Sliding at the contact point between the tire and road is determined using the friction circle approach. Lateral and longitudinal coefficients of friction are based on the sliding velocity. The apparent slip, both lateral and longitudinal, of the tire as it rolls is a direct result of the state of deformation of the tire, and is characterized by relaxation parameters. Deformation state variables also provide the transient response of tire forces.This method does not require the selection of a reference speed and avoids ill-conditioned computations encountered with typical slip ratio and slip angle calculations. As a result it behaves well even at the operating point of the vehicle being completely at rest.