Fuel efficient lubricating composition

Abstract

The instant disclosure is generally directed to low viscosity, low volatility lubricating compositions. The lubricating composition of the instant disclosure includes an oil of lubricating viscosity that contains a lubricating base oil and a hydrocarbon oil. The hydrocarbon oil makes up least 20 wt % of the oil of lubricating viscosity and has a kinematic viscosity of less than 3.7 c St at 100° C. and a NOACK volatility (measured by ASTM D5800) of less than 25 wt %. The lubricant composition further includes a polyalkenyl succinimide dispersant, and, optionally, other formulation additives. The lubricating compositions have been shown to increase fuel economy in internal combustion engines.

1 . A low viscosity, low volatility lubricating composition comprising:
 an oil of lubricating viscosity that includes a lubricating base oil and a hydrocarbon oil, the hydrocarbon oil being at least 20 wt % of the oil of lubricating viscosity and has a kinematic viscosity of less than 3.7 cSt at 100° C. and a NOACK volatility (measured by ASTM D5800) of less than 25 wt %; and   1.2 to 4 wt % of a polyalkenyl succinimide dispersant,   
       the lubricating composition being a 0W-XX multi-grade composition according to SAE J300 and XX is selected from 8, 12, 16, and 20. 
     
     
         2 .- 3 . (canceled) 
     
     
         4 . The composition of  claim 1 , wherein the oil of lubricating viscosity has a viscosity index of greater than 115. 
     
     
         5 .- 8 . (canceled) 
     
     
         9 . The composition of  claim 1 , wherein at least 50 wt % of the hydrocarbon oil is bio-derived. 
     
     
         10 . The composition of  claim 1 , wherein the hydrocarbon oil is a bio-derived and is substantially free of ester functionality. 
     
     
         11 . The composition of  claim 10 , wherein the bio-derived hydrocarbon oil comprises a hydrocarbon compound having a continuous chain of no more than 24 carbon atoms and at least 30 total carbon atoms. 
     
     
         12 . The composition of  claim 1 , wherein the lubricating composition has no more than 10 wt % of a polyalphaolefin base oil. 
     
     
         13 . The composition of  claim 1 , wherein the oil of lubricating viscosity has at least 40 wt % of the hydrocarbon oil. 
     
     
         14 .- 15 . (canceled) 
     
     
         16 . The composition of  claim 1 , wherein the hydrocarbon oil has a kinematic viscosity of less than 3.6 cSt at 100° C. 
     
     
         17 .- 18 . (canceled) 
     
     
         19 . The composition of  claim 1 , wherein the hydrocarbon oil has a NOACK volatility of less than 20 wt %. 
     
     
         20 . (canceled) 
     
     
         21 . The composition of  claim 1 , wherein the hydrocarbon oil comprises a branched hydrocarbon compound containing at least 16 carbon atoms and not more than 60 carbon atoms. 
     
     
         22 . The composition of  claim 1 , wherein the hydrocarbon oil comprises from 20 wt % to 95 wt % of the oil of lubricating viscosity. 
     
     
         23 . The composition of  claim 1 , further comprising a polymeric viscosity modifier present in the lubricating composition in an amount of from 0.05 to 2 wt %. 
     
     
         24 .- 26 . (canceled) 
     
     
         27 . The composition of  claim 1 , wherein the hydrocarbon oil is substantially aliphatic and contains less than 5 wt % cyclic hydrocarbons. 
     
     
         28 . The composition of  claim 1 , wherein the polyalkenyl succinimide dispersant is a polyisobutylene succinimide and is present in the lubricating composition in an amount from 1.2 to 3 wt %. 
     
     
         29 . (canceled) 
     
     
         30 . The composition of  claim 1 , wherein the polyalkenyl dispersant comprises a boron-containing succinimide in an amount of from 0.5 to 4 wt % of the lubricating composition. 
     
     
         31 . The composition of  claim 1 , further comprising an antiwear agent present in the lubricating composition in an amount of from 0.1 to 3 wt %. 
     
     
         32 . (canceled) 
     
     
         33 . The composition of  claim 29 , wherein the antiwear agent is a zinc dialkyldithiophosphate. 
     
     
         34 . The composition of  claim 1 , further comprising a metal-containing detergent present in the lubricating composition in an amount of from 0.5 to 3 wt %. 
     
     
         35 . (canceled) 
     
     
         36 . The composition of  claim 34 , wherein the metal-containing detergent comprises one or more of an overbased calcium detergent, an overbased magnesium detergent, and combinations thereof. 
     
     
         37 . (canceled) 
     
     
         38 . A method of lubricating an internal combustion engine comprising:
 supplying to the internal combustion engine a lubricating composition according to  claim 1 .   
     
     
         39 . (canceled)