Investigation of changes in the properties of engine oil depending on the sulfur content in gasoline

Abstract

In exploitation of modern cars, there are cases of power unit failure due to a sharp deterioration in the properties of engine oil and loss of performance of the lubricant. The article describes the causes of failures of the engines of modern cars associated with the loss of the resource of oil in the engine and the processes occurring in the lubricant. They are increase of kinematic viscosity, decrease of Total Base Number, increase of the acid number, decrease of flash point, increase of water content, decrease of additives content, increase of wear products. Decrease in properties and motor oils lifetime was caused primarily by the deviation of the physicochemical parameters of applied motor gasoline beside regulatory petrol. The process and chemical reaction of sulfurous acid formation during engine operation are described. We have established a pattern of changes in physico-chemical parameters of motor oils in automotive gasoline sulfur compounds. Made quantification is produced by the combustion of 1 kg of gasoline sulfur acid. The low values of the loss of the alkaline number of motor oil, caused by the low sulfur content of the ecological class 5 gasoline, are a prerequisite for an increase periodicity of oil change in the operation of modern cars.