A detailed three-dimensional nonlinear analysis of a tire under the variation of the cord angle is carried out to determine the effects of this change on the deformation and the stress distribution. The tire is assumed to be made of orthotropic composite layers of cord-rubber and is analysed under the inflation and footprint loading. The mechanical properties of the reinforcing cord and the matrix materials are measured in an average manner. The carcass, made of composite laminates, is modeled by shell elements, whereas, the tread, crown, shoulder and the sidewalls are simulated by solid elements.