Low viscosity lubricating oil composition

Abstract

A lubricating oil composition having a high temperature high shear (HTHS) viscosity at 150° C. in a range of about 1.3 to about 2.3 cP is disclosed. The composition comprises (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; (b) an organomolybdenum compound providing 200 to 1500 ppm by weight of molybdenum to the lubricating oil composition; (c) a calcium-containing detergent providing 750 to 3000 ppm by weight of calcium to the lubricating oil composition; (d) a magnesium-containing detergent providing 200 to 1500 ppm by weight of magnesium to the lubricating oil composition; and (e) a viscosity modifier having a PSSI of 30 or less.

1 . A lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.3 to about 2.3 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; 
 (b) an organomolybdenum compound providing 200 to 1500 ppm by weight of molybdenum to the lubricating oil composition; 
 (c) one or more calcium-containing detergents providing 750 to 3000 ppm by weight of calcium to the lubricating oil composition, wherein at least one of the one or more calcium-containing detergents has a total base number (TBN) of from 0 to 80 mg KOH/g; 
 (d) a magnesium-containing detergent providing 200 to 1000 ppm by weight of magnesium to the lubricating oil composition; and 
 (e) a viscosity modifier having a PSSI of 30 or less; wherein the lubricating oil composition is a 0W-8, 0W-12 or 0W-16 SAE viscosity grade. 
 
     
     
         2 . (canceled) 
     
     
         3 . 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. 
     
     
         4 . The lubricating oil composition of  claim 1 , wherein the organomolybdenum compound is a sulfur-containing organomolybdenum compound or a non-sulfur-containing organomolybdenum compound. 
     
     
         5 . The lubricating oil composition of  claim 1 , wherein the organomolybdenum compound is selected from one the group consisting of molybdenum dithiocarbamates, molybdenum dithiophosphates, molybdenum carboxylates, molybdenum esters, molybdenum amines, molybdenum amides, and combinations thereof. 
     
     
         6 . The lubricating oil composition of  claim 1 , wherein the molybdenum amine is a molybdenum-succinimide complex. 
     
     
         7 . The lubricating oil composition of  claim 6 , wherein the succinimide is a C 24  to C 350  alkyl or alkenyl succinimide. 
     
     
         8 . The lubricating oil composition of  claim 6 , wherein the succinimide is a polyisobutenyl succinimide is a reaction product of a C 70  to C 128  polyisobutenyl succinic anhydride and a polyalkylene polyamine selected from triethylenetetramine, tetraethylenepentamine, and combinations thereof. 
     
     
         9 . The lubricating oil composition of  claim 1 , wherein the calcium-containing detergent comprises a calcium sulfonate, a calcium salicylate, and mixtures thereof. 
     
     
         10 . The lubricating oil composition of  claim 1 , wherein the calcium-containing detergent provides 1200 to 1800 ppm by weight of calcium to the lubricating oil composition 
     
     
         11 . The lubricating oil composition of  claim 1 , wherein the magnesium-containing detergent comprises a magnesium sulfonate. 
     
     
         12 . The lubricating oil composition of  claim 1 , wherein the magnesium-containing detergent provides 200 to 800 ppm by weight of magnesium to the lubricating oil composition 
     
     
         13 . The lubricating oil composition of  claim 1 , wherein the mass ratio of calcium metal to magnesium metal is in a range of 1.5 to 3.5. 
     
     
         14 . The lubricating oil composition of  claim 1 , wherein the viscosity modifier is a polyalkylmethacrylate. 
     
     
         15 . The lubricating oil composition of  claim 1 , which is for an internal combustion engine selected from a direct injection spark ignition engine and a port fuel injection spark ignition engine coupled to an electric motor/battery system in a hybrid vehicle. 
     
     
         16 . The lubricating oil composition of  claim 1 , wherein the one or more calcium-containing detergents further includes one or more overbased calcium salicylate detergents. 
     
     
         17 . The lubricating oil composition of  claim 16 , wherein the calcium-containing detergent having a TBN of from 0 to 80 mg KOH/g is a calcium sulfonate detergent. 
     
     
         18 . The lubricating oil composition of  claim 16 , wherein the one or more calcium-containing detergents further includes a first overbased calcium salicylate detergent having a TBN of 150 mg KOH/g or higher and a second overbased calcium salicylate detergent having a TBN of 250 to 450 mg KOH/g. 
     
     
         19 . A lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.3 to about 2.3 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; 
 (b) an organomolybdenum compound providing 200 to 1500 ppm by weight of molybdenum to the lubricating oil composition; 
 (c) a calcium-containing detergent providing 750 to 3000 ppm by weight of calcium to the lubricating oil composition; 
 (d) a magnesium-containing detergent providing 200 to 1000 ppm by weight of magnesium to the lubricating oil composition; and 
 (e) a viscosity modifier having a PSSI of 30 or less; wherein the lubricating oil composition is a 0W-8, 0W-12 or 0W-16 SAE viscosity grade; 
 wherein the lubricating oil composition is devoid of any overbased calcium sulfonate detergent and overbased calcium phenate detergent. 
 
     
     
         20 . The lubricating oil composition of  claim 19 , wherein the calcium-containing detergent comprises a mixture comprising a neutral calcium sulfonate detergent, a first overbased calcium salicylate detergent and a second overbased calcium salicylate detergent.