Medium speed diesel engine oil

Abstract

A lubricating oil having a CCS viscosity at −15° C. less than 7000 cP, good shear stability, and a TBN between 8 and 20 comprising: a) a lubricating base oil made from a waxy feed, b) an engine oil additive package formulated to protect silver bearings, and c) less than 2.0 wt % viscosity index improver. Also a process to make a lubricating oil having a CCS viscosity at −15° C. less than 7000 cP, good shear stability, and a TBN between 8 and 20. Additionally, a lubricating oil having low CCS viscosity comprising specified amounts of lubricating base oil made from a waxy feed, engine oil additive package formulated to protect silver bearings, up to 55 wt % bright stock with a VI greater than 120, and no viscosity index improver or conventional pour point depressant additives. Also, a method for operating a railroad engine using the lubricating oil of this invention.

Dependencies are inferred from the claim text.