A computerized simulation method for evaluating a tire performance is disclosed. Firstly, a simulation of a rolling tire is made by contacting a tire model with a road surface model, and chronological data about node points of the tire model which node points appear in the outer surface of the tire model during rotating are stored. Then, a domain of a fluid is defined, and a simulation of the fluid is made by the use of the chronological data, wherein a small gap is formed between the tire model and the road surface model, and the fluid domain is also defined in the gap.
