Temperature Relations of Selected Engine Oils Dynamic Viscosity

Abstract

This article focuses on temperature relations of dynamic viscosity for selected engine oils. The effect of temperature on new and used oil dynamic viscosity was investigated. Measurements were performed on three different motor oil samples. All the three motor oil samples were synthetic. The first oil sample was new, the second sample was used for 15,000 km, and the third sample was used for 30,000 km. There were made two measurements of samples in one week. Dynamic viscosity was measured using a digital rotational viscometer Anton Paar DV-3P. The principle of measurement is based on the dependence of sample resistance to probe rotation. The results of measurements are shown as graphical relationships between dynamic viscosity and temperature. Decreasing exponential functions in temperature relationships were used for all the samples. The highest difference between the first and second measurement was observed in the new oil, and very small differences were found in other oils. Due to different types of oils and different stage of usage, the results could not be compared.

Effects of Vehicle Mileage Rate on Engine Oil Properties

“…For the new engines (1 and 2), the amount of decrease in fire points was (21.94% and 24.89%). See Figure (6) and Table (5). Although the old engines, (engines 3 and 4) decreased in fire points higher than the new engines, the rate of drop in fire points was (30.38% and 29.95%).…”

“…Although for the old engines (3 and 4) drop in flash point is higher than the new engines, the rate of drop in flash point was (29.33% and 30.22%). See Figure (5) and Table (5). The average difference in the flash point between old and new engines was 5.56%.…”

“…The critical properties parameter for choosing the correct engine lubricant is the kinematic viscosity of the oil. Also, the kinematic viscosity of the lubricant affects the tribological properties of the engine parts, such as the amount of wear and the rate of friction between contact surfaces [5] . The required oil for the engine must retain its properties under different operation conditions, for example, when the load on the engine increases or during running at a cold start [6] .…”