To efficiently and accurately predict the run-flat performance of a tire during travelling.

A friction coefficient between a tire model and a road surface model is set to be a first friction coefficient lower than an actual friction coefficient between a tire and a road surface, a first load greater than a load to be actually applied to the tire is applied to the tire model (Step S103), and the deformation calculation of the tire model is executed (Step S104). Then, the friction coefficient between the tire model and the road surface model is reset to be the actual friction coefficient and the load to be applied to the tire model is reset to be the actual load (Step S105), and the calculation is performed until the tire model is in a balanced condition (Step S106). The obtained tire model is used for evaluating the run-flat performance of the tire to be predicted (Step S107).

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