The objective of the paper is to present the results of an investigation of the effect of reduced tire pressure on car lateral dynamics in lane change maneuver. The intended aim was attained by performing bench and road tests. The aim of the bench tests was parameterization of the mathematical model of the tested car. The road tests covered the vehicle motion with reduced and no tire pressure on a curvilinear track adequate for bypassing an unexpected appearing obstacle. Next, simulations in PC-Crash were performed, and the results were compared with those obtained in experiments.