摘要：The study presents selected results of viscosity tests performed for different temperatures of lubricating oil with viscosity marked as 5w30. Viscosity tests of new oil and oil right after being used have been compared. Lubricating oil used in a drive unit of a passenger car was tested. A vehicle in which oil had been changed irregularly was purposefully selected for the tests. Its mileage was over 15-20 thousand kilometers. Upon testing the vehicle mileage was above 265 thousand kilometers. The values of selected characteristics of the analyzed engine oils have been determined including: density, kinematic viscosity and viscosity index. FUNGILAB rotary viscometer was used for measurement of the oil kinematic viscosity.
