The paper presents research results of a combustion engine ignition start-up process for a city car with the use of a conventional electric starter-motor and with the use of rubber elastic components. The objective of the research work was to compare the ignition dynamics of both concepts and determine the necessary parameters for the rubber elastic components. The results of the performed research contain the course of torque; the energy and power needed for the ignition are shown on the diagrams. A comparison of these two systems shows that the use of the system with the elastic components having reasonable weight is sufficient enough for a reliable ignition and its mechanical parameters are similar to or even better than the electric starter-motor ignition. Positive results became the basis for the initiation of design works on a concept of a new mechanical START-STOP- system. The preliminary assumption as well as the concept of an integrated mechanical device that combines both the engine starter and the energy accumulator have been presented. The last paragraph describes possible advantages of the new START-STOP system, among which the most important are high energy and cost efficiency as well as its simplicity.