摘要：The problems connected with assessment of value changes of selected lubricants during the operation are addressed in this study. The lubricants which have been analyzed are engine oils used in internal combustion drive units of transport means. Selected results of tests of engine oils used for lubrication of passenger car drive units have been presented. The values of kinematic viscosity were determined for different temperatures. In order to evaluate the impact of the oil operation in real working conditions on the viscosity parameters, oil samples were collected from selected vehicles. The vehicles had been used in natural conditions providing transport services. Measurements of kinematic viscosity were performed by means of a rotary viscometer.
