Lubricating oil compositions

摘要

A lubricating oil composition having a sulfur content of up to about 0.4 wt. % and a sulfated ash content of up to about 0.5 wt. % as determined by ASTM D874 is disclosed which comprises (a) a major amount of an oil of lubricating viscosity; (b) at least one oil-soluble or dispersed oil-stable boron-containing compound having no more than about 600 ppm of boron, based upon the total mass of the composition; and (c) at least one oil-soluble or dispersed oil-stable molybdenum-containing compound having no more than about 800 ppm of molybdenum, based upon the total mass of the composition; wherein the lubricating oil composition has a ratio of sulfur to molybdenum of about 5:1 to about 500:1.