No abstract

Engine oil is an important element in the design of an internal combustion engine and can provide a given resource only if its properties correspond to the thermal, mechanical and chemical influences to which it is subjected in the lubrication system and on the surfaces of parts heated to high temperatures and in the friction zone. Based on the analysis of control methods and processes occurring in engine oils, the main indicators that characterize their quality are thermal–oxidative stability, temperature resistance, lubricating properties and viscosity, which determine the resource of the engine oil. However, these indicators are mainly used in the control of oil production and are not widely used in the operation of various equipment. In addition, the influence of oxidation products on the kinematic viscosity, viscosity index, anti–wear properties and service life of lubricating oils, and most importantly, the mechanism of formation of temperature control products, their structure and energy consumption, are not sufficiently studied. therefore, the purpose of these studies is to determine the potential service life of motor oils, as well as the influence of oxidative processes on the viscosity–temperature characteristics of motor oils and to justify the criteria for their evaluation. This paper presents the results of a study of the effect of oxidative processes on the viscosity–temperature characteristics of partially synthetic motor oils: Castrol Magnatec 10W–40 and Rosneft Maximum 10W–40 SL/CF. at temperature control temperatures of 180.170 and 160°C. The potential resource and the criterion of the viscosity–temperature characteristic determined by the product of the optical density and the viscosity index are proposed as an indicator for justifying the maximum permissible temperature of the working capacity of motor oils.