METHOD OF LUBRICATING AN INTERNAL COMBUSTION ENGINE AND IMPROVING THE EFFICIENCY OF THE EMISSIONS CONTROL SYSTEM OF THE ENGINE
摘要
An internal combustion engine with a catalyst-containing exhaust-gas aftertreatment device is lubricated with a composition of a base oil; and a zinc salt of a mixture of phosphorus-containing compounds having hydrocarbyl groups R<SUP>1</SUP> and R<SUP>2 </SUP>where the average total number of carbon atoms in R<SUP>1</SUP> plus R<SUP>2</SUP> for the mixture of phosphorus-containing compounds is at least 9.5, where 4 to 30 weight percent of such groups contain 2 to 4 carbon atoms and where in less than 8 mole percent of the phosphorus-containing molecules in the mixture of phosphorus- containing compounds each of R<SUP>1</SUP> and R<SUP>2</SUP> contain 2 to 4 carbon atoms.
