A 3D finite element (FE) model of a radial tire 205/55R16, established using ABAQUS software, is utilized to simulate tire force and moment properties. Drum tests are designed to validate the FE model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented. Based on string balance contour theory, it simplifies the shape of belt pressure share ratio as a trapezium. Besides, a program for calculating tire contour curve is compiled using MATLAB software. Applying different belt pressure share ratios, diverse tire contours are designed. One of the contours is selected according to its positive effect on cornering stiffness in simulation. From comparison of the selected newly designed tire and the original tire, it is found that the newly designed tire’s contact patch area, longitudinal stiffness, lateral stiffness, inclination stiffness and cornering stiffness increase while its radial stiffness decreases. The results show that the new contour design theory can improve tire force and moment properties, thus improving vehicle handling and riding comfort performances.