In modern conditions of market competition leading manufacturers of wheeled vehicles and their components actively introduce new technologies in the process of production of their products. One of the directions of modern automobile industry development is application of new materials, which include polymeric composite materials (PCM). In the given research the analysis of elastic properties of a leaf spring made of application of polymeric composite materials is carried out. In the study the analysis of the construction by finite element (FE) method and the analysis of the results of bench tests are carried out. To carry out the research, the appropriate design was made, the methods of testing of the elastic element under consideration were developed, the composite spring was mathematically simulated for the purpose of its verification and the possibility of its further use. As a result of the work performed, the maximum deflections of the leaf spring under consideration were established when loading the corresponding load in the suspension system of GAZ-2752 "Sobol" car. The executed bench experiment has established he maximum deflection of a spring. Similar values were obtained by the FE-method. These results show that it is impossible to use the leaf spring in the suspension system of a GAZ-2752 car.