Study of temperature dependent viscosity of different types of engine used oils

Abstract

Abstract The article presents a study on the change in kinematic viscosity with the temperature for three samples of synthetic used oil (SAE 5W-30). Samples were taken after a 10,000 km run on the occasion of periodically changing oil from three engines with close cylindrical capacities (one diesel engine – VW 1.9 TDI, one gasoline engine – Audi 1.8 Turbo and one spark engine – Audi 1.8 Turbo, working with GPL). Comparatively, viscosity measurements were made for the same oils before being introduced into the engines. The kinematic viscosity was measured experimentally using the Brookfield viscometer from 5 to 5 degrees Celsius. To eliminate the errors, the measurements were made under the same conditions for all samples, being repeated three times, the values taken into consideration for a given temperature being made up of averages of the three measurements.