Lubricant formulations and methods

Abstract

The embodiments described herein relate to particular formulations and methods that may provide improved fuel economy characteristics for an engine lubricant. The compositions and methods include a (a) a base oil; (b) a zinc dialkyldithiophosphate compound; and (c) a hydrocarbon soluble metal compound. The hydrocarbon soluble metal compound is devoid of phosphorus and sulfur atoms and the metal is selected from the group consisting essentially of selected from the group consisting essentially of cobalt, nickel, zinc, zirconium, manganese, vanadium, scandium, yttrium, tungsten, gold, platinum, and iron. A weight ratio of total metal in the lubricant composition from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the lubricant composition ranges from greater than about 1.5 to 1 to about 15 to 1.

1 . A lubricant composition for providing improved friction characteristics:
 (a) a base oil;   (b) a zinc dialkyldithiophosphate compound; and   (c) a hydrocarbon soluble metal compound, wherein the hydrocarbon soluble metal compound is devoid of phosphorus and sulfur atoms and the metal is selected from the group consisting essentially of cobalt, nickel, zinc, zirconium, manganese, vanadium, scandium, yttrium, tungsten, gold, platinum, and iron,   
       wherein a weight ratio of total metal in the lubricant composition from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the lubricant composition ranges from greater than about 1.5 to 1 to about 15 to 1. 
     
     
         2 . The lubricant composition of  claim 1 , wherein the lubricant composition is an engine oil. 
     
     
         3 . The lubricant composition of  claim 1 , wherein the lubricant composition is a heavy duty engine oil. 
     
     
         4 . The lubricant composition of  claim 1 , wherein the base oil comprises a mineral oil, a synthetic oil, or a mixture thereof. 
     
     
         5 . The lubricant composition of  claim 1 , wherein the base oil comprises on or more of a member selected from the group consisting of: a group I base oil, a group II base oil, a group III base oil, a group IV base oil, and a group V base oil. 
     
     
         6 . The lubricant composition of  claim 1 , wherein a total amount of metal in the lubricant composition from the zinc dialkyldithiophosphate compound and the hydrocarbon soluble metal compound ranges from about 300 to about 1500 ppm by weight based on the total weight of the lubricant composition. 
     
     
         7 . The lubricant composition of  claim 1 , wherein a total amount of phosphorus in the lubricant composition from the zinc dialkyldithiophosphate compound ranges from about 200 to about 1000 ppm by weight based on the total weight of the lubricant composition. 
     
     
         8 . The lubricant composition of  claim 1 , wherein a boundary friction characteristic at 130° C. is less than a boundary friction characteristic at 130° C. of a lubricant composition comprising zinc dialkyldithiophosphate and having a total metal to phosphorus weight ratio of less than about 1.5 to 1, wherein the lubricant composition is devoid of the hydrocarbon soluble metal compound. 
     
     
         9 . The lubricant composition of  claim 1 , wherein a boundary friction characteristic at 130° C. is less than a boundary friction characteristic at 130° C. of a lubricant composition comprising zinc dialkyldithiophosphate, wherein the lubricant composition is devoid of the hydrocarbon soluble metal compound. 
     
     
         10 . The lubricant composition of  claim 1 , wherein the weight ratio of total metal in the lubricant composition from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the lubricant composition ranges from greater than about 3.0 to 1 to about 10 to 1. 
     
     
         11 . An additive concentrate for an engine crankcase lubricant comprising:
 (a) a zinc dialkyldithiophosphate compound; and   (b) a hydrocarbon soluble metal compound other than a dispersant or a detergent,   
       wherein the hydrocarbon soluble metal compound is devoid of phosphorus and sulfur atoms and the metal is selected from the group consisting essentially of cobalt, nickel, zinc, zirconium, manganese, vanadium, scandium, yttrium, tungsten, gold, platinum, and iron, wherein a weight ratio of total metal in the concentrate from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the concentrate ranges from greater than about 1.5 to 1 to about 15 to 1. 
     
     
         12 . The additive concentrate of  claim 11 , wherein the additive concentrate provides a total amount of metal from the zinc dialkyldithiophosphate compound and the hydrocarbon soluble metal compound to a lubricant composition containing the concentrate ranging from about 300 to about 1500 ppm by weight based on the total weight of the lubricant composition. 
     
     
         13 . The additive concentrate of  claim 11 , wherein the additive concentrate provides a total amount of phosphorus from the zinc dialkyldithiophosphate compound to a lubricant composition containing the concentrate ranging from about 200 to about 1000 ppm by weight based on the total weight of the lubricant composition. 
     
     
         14 . A method for improving a fuel economy of an internal combustion engine, comprising lubricating the engine with a lubricant composition comprising:
 (a) a base oil;   (b) a zinc dialkyldithiophosphate compound; and   (b) a hydrocarbon soluble metal compound other than a dispersant or a detergent,   
       wherein the hydrocarbon soluble metal compound is devoid of phosphorus and sulfur atoms and the metal is selected from the group consisting essentially of cobalt, nickel, zinc, zirconium, manganese, vanadium, scandium, yttrium, tungsten, gold, platinum, and iron, wherein a weight ratio of total metal in the concentrate from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the lubricant composition ranges from greater than about 1.5 to 1 to about 15 to 1. 
     
     
         15 . The method of  claim 14 , wherein a total amount of metal in the lubricant composition from the zinc dialkyldithiophosphate compound and the hydrocarbon soluble metal compound ranges from about 300 to about 1500 ppm by weight based on the total weight of the lubricant composition. 
     
     
         16 . The method of  claim 14 , wherein a total amount of phosphorus in the lubricant composition from the zinc dialkyldithiophosphate compound ranges from about 200 to about 1000 ppm by weight based on the total weight of the lubricant composition. 
     
     
         17 . The method of  claim 14 , wherein a boundary friction characteristic at 130° C. is less than a boundary friction characteristic at 130° C. of a lubricant composition comprising zinc dialkyldithiophosphate and having a total metal to phosphorus weight ratio of less than about 1.5 to 1, wherein the lubricant composition is devoid of the hydrocarbon soluble metal compound. 
     
     
         18 . A method for improving a friction characteristic of a lubricant for an internal combustion engine, comprising formulating a lubricant composition with:
 (a) a base oil;   (b) a zinc dialkyldithiophosphate compound; and   (b) a hydrocarbon soluble metal compound other than a dispersant or a detergent,   
       wherein the hydrocarbon soluble metal compound is devoid of phosphorus and sulfur atoms and the metal is selected from the group consisting essentially of cobalt, nickel, zinc, zirconium, manganese, vanadium, scandium, yttrium, tungsten, gold, platinum, and iron, wherein a weight ratio of total metal in the concentrate from the zinc dialkyl-dithiophosphate compound and the hydrocarbon soluble metal compound to phosphorus in the lubricant composition ranges from greater than about 1.5 to 1 to about 15 to 1. 
     
     
         19 . The method of  claim 18 , wherein a total amount of metal in the lubricant composition from the zinc dialkyldithiophosphate compound and the hydrocarbon soluble metal compound ranges from about 300 to about 1500 ppm by weight based on the total weight of the lubricant composition. 
     
     
         20 . The method of  claim 18 , wherein a total amount of phosphorus in the lubricant composition from the zinc dialkyldithiophosphate compound ranges from about 200 to about 1000 ppm by weight based on the total weight of the lubricant composition. 
     
     
         21 . The method of  claim 18 , wherein a boundary friction characteristic at 130° C. is less than a boundary friction characteristic at 130° C. of a lubricant composition comprising zinc dialkyldithiophosphate and having a total metal to phosphorus weight ratio of less than about 1.5 to 1, wherein the lubricant composition is devoid of the hydrocarbon soluble metal compound.