Thermal‐mechanical properties of tire cords have a great influence on tire dimension, shape, handling, and other performance related issues. This study focuses on characterizing the material properties for polymeric cords and quantifying their effects on pneumatic tires using finite element analysis (FEA). Various tire cord materials, including nylon and polyester, were characterized by obtaining a series of thermal‐mechanical properties in the laboratory using tensile testing, thermal shrinkage measurement and creep testing. Prior to obtaining these laboratory measurements, cords in this study were subjected to thermal‐mechanical pre‐treatments to simulate the effects of curing and tire operating conditions. The properties derived from these measurements were used as input properties for a finite element analysis of a physical tire. Predictions of tire dimensions and shape, loaded footprint and pressure and cord loads were obtained from the FEA model and compared to measured values of the experimental tire. Good agreement was observed between the measured values and those predicted from the finite element analysis; therefore, future FEA studies of pneumatic tires should utilize the techniques developed in this study to characterize tire cord materials.