Engine lubricant

Abstract

Lubricant compositions and methods related thereto. Lubricant compositions may comprise a first and a second oil base stock. A first oil basestock may be an API group I or group II basestock. A second oil basestock may comprise an API group II extra heavy basestock. Lubricant compositions may include about 40-60 mass % of a first oil base stock, and about 20-45 mass % of a second oil basestock. An API group II extra heavy basestock may have: a kinematic viscosity (ASTM D445, 40° C.) of 320-520 cSt, a kinematic viscosity (ASTM D445, 100° C.) of 22-36 cSt, a viscosity index (ASTM D2270) of 80-119, a pour point (ASTM D97) of −6° C. or less, and/or a saturate content of 90 mass % or greater. A lubricant composition may have application as an engine oil. Methods of operating an engine may comprise using the engine oil.

What is claimed is: 
     
         1 . A lubricant composition for use as an engine oil, comprising:
 about 40 mass % to about 60 mass % of a first oil base stock, wherein the first oil basestock is an API group I basestock or API group II basestock;   about 20 mass % to about 45 mass % of a second oil basestock, wherein the second oil basestock comprises an API group II extra heavy basestock, and wherein the API group II extra heavy basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of 320 cSt to 520 cSt, 
 a kinematic viscosity (ASTM D445, 100° C.) of 22 cSt to 36 cSt, 
 a viscosity index (ASTM D2270) of 80 to 119, 
 a pour point (ASTM D97) of −6° C. or less, and 
 a saturate content (ASTM D7419) of 90 mass % or greater. 
   
     
     
         2 . The lubricant composition of  claim 1 , wherein the first oil comprises substantially no group I high viscosity bright stock. 
     
     
         3 . The lubricant composition of  claim 1 , wherein the first oil comprises less than 1 mass % of API group I high viscosity bright stock. 
     
     
         4 . The lubricant composition of  claim 1 , wherein the first oil basestock comprises an API group I basestock, and wherein the API group I basestock has:
 a kinematic viscosity (ASTM 445, 40° C.) of 15 cSt to 80 cSt, and   a pour point (ASTM D97) of −9° C. or less.   
     
     
         5 . The lubricant composition of  claim 1 , wherein the first oil basestock comprises an API group II basestock, and wherein the API group II basestock has:
 a kinematic viscosity (ASTM 445, 100° C.) of 5 cSt to 10 cSt, and   a pour point (ASTM D97) of −10° C. or less.   
     
     
         6 . The lubricant composition of  claim 1 , wherein the lubricant composition a kinematic viscosity (ASTM D445, 100° C.) of 12.5 cSt to 26.1 cSt. 
     
     
         7 . The lubricant composition of  claim 1 , wherein the lubricant composition has a pour point (ASTM D97) of −21° C. or less. 
     
     
         8 . The lubricant composition of  claim 1 , wherein the lubricant composition has a NOACK Volatility (ASTM D5800) of 18 mass % or less. 
     
     
         9 . The lubricant composition of  claim 1 , wherein the lubricant composition has a NOACK Volatility (ASTM D5800) from 5 mass % to 15 mass %. 
     
     
         10 . The lubricant composition of  claim 1 , wherein the lubricant composition has a Cold-Cranking Simulator test result (ASTM D5293, −15° C.) of 10,000 cP or less. 
     
     
         11 . The lubricant composition of  claim 1 , wherein the lubricant composition has a Viscometer Yield Strength (ASTM D4684, −25° C.) of 35 Pa or less. 
     
     
         12 . The lubricant composition of  claim 1 , wherein the lubricant composition has an Apparent Viscosity (ASTM D4684, −25° C.) of 60,000 cP or less. 
     
     
         13 . The lubricant composition of  claim 1 , wherein the lubricant composition comprises about 5 mass % or less viscosity modifier. 
     
     
         14 . The lubricant composition of  claim 1 , wherein the lubricant composition meets or exceeds standards for SAE 20W-50. 
     
     
         15 . The lubricant composition of  claim 1 , wherein the API group II extra heavy basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of 460 cSt to 520 cSt,   a kinematic viscosity (ASTM D445, 100° C.) of 32 cSt to 36 cSt,   a viscosity index (ASTM D2270) of 80 to 119,   a pour point (ASTM D97) of −15° C. or less, and   a saturate content (ASTM D7419) of 98 mass % or greater.   
     
     
         16 . A method comprising operating an engine with an engine oil, the engine oil comprising:
 about 40 mass % to about 60 mass % of a first oil base stock, wherein the first oil basestock is an API group I basestock or API group II basestock;   about 20 mass % to about 45 mass % of a second oil basestock, wherein the second oil basestock comprises an API group II extra heavy basestock, and wherein the API group II extra heavy basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of 320 cSt to 520 cSt, 
 a kinematic viscosity (ASTM D445, 100° C.) of 22 cSt to 36 cSt, 
 a viscosity index (ASTM D2270) of 80 to 119, 
 a pour point (ASTM D97) of −6° C. or less, and 
 a saturate content (ASTM D7419) of 90 mass % or greater. 
   
     
     
         17 . The method of  claim 16 , wherein the API group II extra heavy basestock has:
 a kinematic viscosity (ASTM D445, 40° C.) of 460 cSt to 520 cSt,   a kinematic viscosity (ASTM D445, 100° C.) of 32 cSt to 36 cSt,   a viscosity index (ASTM D2270) of 80 to 119,   a pour point (ASTM D97) of −15° C. or less, and   a saturate content (ASTM D7419) of 98 mass % or greater.