Abstract
From the end of the 1990s to the beginning of the 2000s, engine manufacturers have developed high-output, high-efficiency engines. At the same time engine manufacturers have improved cylinder lubrication. However, emission regulation requires a low base number cylinder oil for low sulfur fuel. Oil suppliers have been developing products corresponding to these demands. In order to understand recent technology trends in lubricants (system oil and cylinder oil) for two-stroke crosshead diesel engines, the performance of formulations a decade ago and the latest ones are compared. The deposit formation control performance of system oils differ, depending on brand. High temperature extreme pressure properties and high temperature detergency, of high base number cylinder oils, was improved about 20 degree C over the past ten years. Moreover, low base number cylinder oils and universal cylinder oils developed after 2000 have a higher temperature extreme pressure property, and a higher temperature detergency and oxidation stability equivalent when compared with the latest high base number cylinder oils.
