Low viscosity engine oils containing isomerized phenolic-based detergents

Abstract

This disclosure generally relates to a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.3 to about 2.5 cP, comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. in a range of 1.5 to 6.0 mm 2 /s; and (b) an overbased metal salt of an alkyl-substituted detergent.

What is claimed is: 
     
         1 . A lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.3 to about 2.5 cP, comprising:
 (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. in a range of 1.5 to 6.0 mm 2 /s; and 
 (b) an overbased metal salt of an alkyl-substituted phenolic-based detergent, wherein the alkyl group is derived from an isomerized normal alpha olefin having from about 10 to about 40 carbon atoms per molecule having an isomerization level (I) of the normal alpha olefin of from about 0.1 to about 0.4. 
 
     
     
         2 . The lubricating oil composition of  claim 1 , wherein the alkyl-substituted phenolic-based detergent is selected from the group consisting of a non-sulfur containing phenate, sulfur-containing phenate, a naphthenate, a complex detergent, a salixarate, a salicylate, a saligenin, a calixarene, sulfur-bridged alkylphenols, alkylene-bridged alkylphenols, and mixtures thereof. 
     
     
         3 . The lubricating oil composition of  claim 1  wherein the alkyl-substituted phenolic-based detergent is a carboxylate or a salicylate detergent, wherein the alkyl group is derived from an isomerized alpha olefin having from about 10 to about 40 carbon atoms per molecule having an isomerization level (I) of the normal alpha olefin of from about 0.1 to 0.4. 
     
     
         4 . The lubricating oil composition of  claim 1  wherein the alkyl-substituted phenolic-based detergent is an isomerized olefin phenate detergent, wherein the alkyl group is derived from an isomerized alpha olefin having from about 10 to about 40 carbon atoms per molecule having an isomerization level (I) of the normal alpha olefin of from about 0.1 to 0.4. 
     
     
         5 . The lubricating oil composition of  claim 1 , wherein the overbased metal salt is calcium, magnesium, or a combination thereof. 
     
     
         6 . The lubricating oil composition of  claim 1 , wherein the lubricating oil composition is a 0W-8, 0W-12 or 0W-16 SAE viscosity grade. 
     
     
         7 . The lubricating oil composition of  claim 1 , wherein the oil of lubricating viscosity is a base oil selected from one or more of API Group II, Group III, Group IV, and Group V. 
     
     
         8 . The lubricating oil composition of  claim 1 , wherein the isomerized normal alpha olefin has an isomerization level (I) of the normal alpha olefin of from about 0.12 to about 0.3. 
     
     
         9 . The lubricating oil composition of  claim 1 , wherein the isomerized normal alpha olefin has an isomerization level (I) of the normal alpha olefin of about 0.16. 
     
     
         10 . The lubricating oil composition of  claim 1 , wherein the isomerized normal alpha olefin has an isomerization level (I) of the normal alpha olefin of about 0.26. 
     
     
         11 . The lubricating oil composition of  claim 1 , wherein the normal alpha olefin mixture has from about 14 to about 28 carbon atoms per molecule. 
     
     
         12 . The overbased phenolic-based detergent of  claim 1  wherein the normal alpha olefin mixture has from about 18 to about 24 carbon atoms per molecule. 
     
     
         13 . The overbased phenolic-based detergent of  claim 1  wherein the normal alpha olefin mixture has from about 20 to about 24 carbon atoms per molecule. 
     
     
         14 . The lubricating oil composition of  claim 1 , wherein the TBN of the detergent is from 100 to 600 mg KOH/gram on an oil free basis. 
     
     
         15 . The lubricating oil composition of  claim 1 , further comprising an additional detergent selected from the group consisting of sulfonate, phenate, and salicylate. 
     
     
         16 . The lubricating oil composition of  claim 15 , wherein the detergent is a magnesium sulfonate. 
     
     
         17 . The lubricating oil composition of  claim 1 , further comprising a polymethacrylate dispersant VII. 
     
     
         18 . The lubricating oil composition of  claim 1 , further comprising a primary or secondary zinc dithiophosphate compound or a mixture thereof. 
     
     
         19 . The lubricating oil composition of  claim 1 , further comprising a friction modifier. 
     
     
         20 . A method of lubricating an engine comprising lubricating said engine with a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.3 to about 2.5 cP, comprising:
 (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. in a range of 1.5 to 6.0 mm 2 /s; and 
 (b) an overbased metal salt of an alkyl-substituted phenolic-based detergent, 
 
       wherein the alkyl group is derived from an isomerized normal alpha olefin having from about 10 to about 40 carbon atoms per molecule having an isomerization level (I) of the normal alpha olefin of from about 0.1 to about 0.4.