Introduction. The reasons for the formation of an increased amount of condensate in the exhaust system of a car at a low ambient temperature are considered. Since the speed of the vehicle is one of the factors that determine the heating of the exhaust system and the formation of condensation, an experimental study was carried out to determine the temperature of the elements of the exhaust system at various vehicle speeds.The purpose of this study: to establish the features of the temperature change of individual elements of the exhaust system, depending on time at different vehicle speedsMaterials and methods. The sequence of the experimental study consisted of starting the “cold” engine, accelerating the car and then moving the car at a constant speed for 20 minutes. Simultaneously with the start of the engine, the temperature of the elements of the exhaust system was recorded. In this study, thermocouples were used to measure the surface temperature of the exhaust system. Experimental studies were carried out on a Toyota Camry with a gasoline engine in the climatic conditions of the Perm Territory.Results. The dependences of the temperature of the exhaust system elements on time were obtained at different speeds. In an experimental study, it was found that the temperature of the elements of the exhaust system is established within 8-12 minutes from the start of the vehicle at a constant speed; the rear muffler has the least surface heating, and therefore the greatest probability of the formation and accumulation of condensate.Discussion and conclusion. The analysis of the peculiarities of the change in the temperature of the exhaust system during the movement of the vehicle in conditions of low ambient temperature is carried out. The established patterns can be used to obtain information on the processes of condensate accumulation in the exhaust system and are aimed at predicting the amount of condensate accumulation in the exhaust system; to develop new solutions to ensure reliable operation of the exhaust system.

Currently operation of cars in large cities in winter is the most unfavorable from the point of view of the risk of blocking the exhaust system by condensate accumulated in it. Frequent starts during relatively short period of time, or the cycle of start-up – short run – and subsequent long-term parking at low temperatures are dangerous because the exhaust system does not have time to warm up and remove the accumulated condensate. Daily operation in such modes contributes to rapid accumulation of condensate, and subsequent long-term parking at ambient temperatures below 0˚C are equally dangerous because, depending on the design features of the exhaust system elements, condensation may occur and freeze in the exhaust system, icing can occur inside it or at its exit, causing inability to start the engine. Given that most of the territory of Russia is located in the areas of moderate and cold climate, the relevance of studies, aimed at identifying the patterns of condensate formation and accumulation in the exhaust system, at adjusting on this basis the frequency of condensate removal from the exhaust system, as well as at optimizing the design parameters of the exhaust systems, is quite evident. The objectives of this study were: to identify the features of changes in temperature of the elements of the exhaust system when the automobile engine warms up at low ambient temperature, the effect of various modes of the heater operation on the temperature of the elements of the exhaust system, as well as the features of the temperature change of individual elements of the exhaust system depending on time for various ambient temperatures. To achieve those objectives a series of experiments has been conducted to study the process of starting the «cold» engine, and of its warming up in idle mode. The found dependencies can be used to develop methodology to adjust the recommended periodicity of warming up of the exhaust system, as well as a model of a device that will ensure the absence of condensate in exhaust systems during the operation of cars in large cities during winter period.