As experts predict, in a few years the share of cars equipped with the Start-Stop system will reach about 70-80% of the total production volume. It means that sooner or later we will have to deal with this "patchwork" as well. What immediately raises a number of questions: what is the reason for the popularity of the Start-Stop system among manufacturers, what are its advantages, and what are the disadvantages, especially after several years of operation? Why is this necessary and how it works? Although many manufacturers are actively working in "promising" areas, experimenting with hydrogen cars, electric cars, hybrids, it is necessary to fit into all the toughening environmental requirements right now, on mass-produced models with traditional motors. Various technical solutions are in use, including the Start-Stop system. According to the developers, it saves up to 8% of the fuel and, accordingly, contributes to the reduction of carbon dioxide emissions into the atmosphere, which is