Tire model is one of the most important components of vehicle dynamic simulation because it is responsible for calculating major external forces and moments acting on a vehicle. The conventional modeling approach relies on empirical formula, hence, the resulting model cannot account for the effect of temperature and inflation pressure changes that occur during handling test maneuvers. In this study, a physical tire model is proposed based on the brush model with flexible carcass. Its parameters are determined by using indoor tire force and moment measurements along with footprint data. The model parameters for tires with different sizes and design specifications are obtained at several temperature and inflation pressure conditions. Based on the results, the parameters are modeled as functions of tire tread temperature and inflation pressure. The brush model is combined with a simple thermal model so that the temperature and inflation pressure changes are predicted and their effect is taken into the calculation of tire forces and moments. As a result, the vehicle dynamic simulation can be performed using the tire force and moment estimated for the thermal state of each time step. The proposed tire modeling scheme is validated by comparing the simulation results to the Flat-trac measurement data. In addition, the relationship between the tire model parameters and design specification is analyzed. The method of predicting the effect of tire size change and design modification on tire force and moment is discussed.