PURPOSE. The purpose of the paper is to justify the need for a scientific selection of a series of tire profiles when replacing tires in order to ensure vehicle safety. METHODS. The study uses the methods of mathematical statistics, mathematical modeling and provides a detailed analysis of the scientific and technical documentation on the topic of the research. RESULTS AND THEIR DISCUSSION. The article presents the statistical data on the wear of tire protector and shock absorbers and provides the criteria for the critical threshold of their life. Description is given to the selection features of lower series tire replacement. The results and analysis of comparative tests on the evaluation of shock absorber wear effect on the braking length of vehicles equipped and not equipped with ABS and ESP systems are presented. A formula is given for determining the conditional probability of the coincidence between the road accident and vehicle movement with wheel breakaways from the road. The results of calculations by the formula are presented as well. It is concluded that this probability can be more than 20% for road conditions in the territory of the Russian Federation. The amplitude-frequency characteristics of the relative accelerations of the vehicle body and wheel movements are constructed and analyzed. It is noted that the replacement of worn tires with the tires of a lower profile even if shock absorbers are serviceable significantly raises wheel vibrations (2 times), which increases the likelihood of wheel breakaway from the road and reduces the safety of motor vehicles. CONCLUSIONS. It is necessary to develop a methodology for scientifically based selection of a tire profile series when replacing tires taking into account the condition of shock absorbers in order to improve the safety of motor vehicles.