Engine oil formulations for biodiesel fuels
AssigneeThe Lubrizol Corporation
InventorsJola Adamczewska, Mark C. Davies, Craig J. Jones
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Abstract
The lubricant for an internal combustion engine fueled by a biodiesel fuel (that is, a liquid fuel containing a C1-C4 alkyl ester of a carboxylic acid of about 12 to about 24 carbon atoms) exhibits improved resistance to oxidative degradation when the lubricant contains an alkali metal detergent.
Claims16
A method for lubricating a sump-lubricated internal combustion engine fueled by a liquid fuel which comprises a middle distillate fuel and about 2 to about 50 percent by weight of a C1-C4 alkyl ester of a carboxylic acid of about 12 to about 24 carbon atoms, comprising supplying to the sump a lubricant comprising a mineral oil of lubricating viscosity, and a minor amount of an oil-soluble overbased sodium sulfonate detergent which is present at about 0.02 to about 5 percent by weight of the lubricant composition, being in an amount to provide about 250 to about 5000 parts by million by weight of sodium to the lubricant composition.
A lubricant composition comprising
- (a) a mineral oil of lubricating viscosity;
- (b) at least about 1 percent by weight of a C1-C4 alkyl ester of a carboxylic acid of about 12 to about 24 carbon atoms, which arises from dilution of the lubricant by a liquid fuel which comprises a middle distillate fuel and about 2 to about 50 percent by weight of said ester;
- and
- (c) a minor amount of an oil-soluble overbased sodium sulfonate detergent which is present at about 0.02 to about 5 percent by weight of the lubricating composition, being in an amount to provide about 250 to about 5000 parts by million by weight of sodium to the lubricant composition.
A method of reducing oxidative degradation of a lubricant composition which contains an oil of lubricating viscosity and at least about 1 percent by weight of a C1-C3 alkyl ester of a carboxylic acid of about 12 to about 24 carbon atoms, which arises from dilution of the lubricant by a liquid fuel which comprises a middle distillate fuel and about 2 to about 50 percent by weight of said C1-C3 alkyl ester, comprising including within said lubricant composition a minor amount of an oil-soluble overbased sodium sulfonate detergent, which is present in an amount of about 0.01 to about 5 percent by weight of the lubricant composition and to provide about 250 to about 5000 parts by million by weight of sodium to the lubricant composition.
Dependencies are inferred from the claim text.