The operational structure and use of the “General Motors Research Laboratories Combined Thermo-Mechanical Tire Power Loss Model” are presented in this paper. The modular format of this tire power loss model is briefly reviewed. Descriptions of its three major analysis modules -- thermal, dissipation, and deformation -- are given. A flow chart is presented showing how these modules are interfaced to form an interactive, iterative model. Steps required to operate this model, procedures necessary to obtain and prepare the input data, and sample results obtained using the model are presented.