In terms as close as possible to mathematical theory of reliability, the nature of the loss and restoration of cars is described, considered as probabilistic system aging elements with incomplete recovery. Analytical researches showed that the flow of demands for the system of maintenance and repair (SMR) of the cars presented thus is described by the composition of laws of distribution which decision leads to analytically unsoluble multidimensional integrals. Consequently, traditional economic and mathematical models in which the analogue of the object of research used analytical expressions can't be used in the solution of tasks on further improvement of the system resistance machines aging on correct scientific grounds. It is shown that in the course of maintenance of cars continuous redistribu- tion of resources of their components happens opera- tions of repair and replacement, as a result each indi-vidual car is characterized by uncertainty of technical condition in time. It is shown that in the process of resto- ration of cars operations repair and replacement is con- stant reallocation of resources to their constituent parts, as a result, each individual vehicle is characterized by the uncertainty of technical condition in time. In this re- gard, there is a deep contradiction between the current regulatory system of maintenance based on the use of the quality standards prescribed frequency, and the actual technical condition of the car at the time of con- trol. Overcoming this contradiction is possible by the justification and use of essentially new standards on the contents operating the content of the repair serving works (RSW). The essential role of preventive mainte- nance operations in terms of the high risks of production losses was established. Accepted interpretation of de- scribed process opens up the possibility of developing effective practical methods to justification of resource- saving technologies used in the system of technical service of cars.