Low-sulfur consumable lubricating oil composition and a method of operating an internal combustion engine using the same

Abstract

This invention relates to a low-sulfur consumable lubricating oil composition, comprising: a base oil; an acylated nitrogen-containing compound having a substituent of at least about 10 aliphatic carbon atoms; and a sulfur content of about 5 to about 250 ppm; said composition being characterized by the absence of an extreme-pressure additive comprised of metal and phosphorus. This invention further relates to a a method of operating an internal combustion engine equipped with an exhaust gas aftertreatment device, said method comprising: (A) operating said engine using a normally liquid or gaseous fuel; (B) lubricating said engine using the foregoing low-sulfur consumable lubricating oil composition; (C) removing part of said low-sulfur consumable lubricating oil composition from said engine, said removed part of said low-sulfur consumable lubricating oil composition (i) being combined with said fuel and consumed with said fuel as said engine is operated or (ii) being combined with the exhaust gas from said engine and removed from said engine with said exhaust gas; and (D) adding an additional amount of said low-sulfur consumable lubricating oil composition to said engine to replace said removed part of said low-sulfur consumable lubricating oil composition.

Dependencies are inferred from the claim text.