Lubricating oil composition

Abstract

Lubricating oil compositions containing a major amount of oil of lubricating viscosity, an oil soluble molybdenum compound in an amount providing the composition with from 0.001 to 0.1 mass % molybdenum, an oil soluble copper antioxidant in an amount providing the composition with from 0.001 to 0.02 mass % copper to said composition, and an amount of metal hydrocarbyl dithiophosphate providing the composition with from 100 to 550 ppm phosphorus.

What is claimed is:  
     
         1 . A lubricating oil composition comprising a major amount of oil of lubricating viscosity, an oil soluble molybdenum compound in an amount providing from 0.001 to 0.01 mass % molybdenum to said composition, an oil soluble copper antioxidant in an amount providing from 0.001 to 0.02 mass % copper to said composition, and an amount of metal hydrocarbyl dithiophosphate providing said composition with from 100 to 550 ppm phosphorus.  
     
     
         2 . The lubricating oil composition of  claim 1 , wherein said metal hydrocarbyl dithiophosphate is zinc dialkyl dithiophosphate.  
     
     
         3 . The lubricating oil composition of  claim 1 , wherein said composition has a Noack volatility of no greater than 15 wt. %.  
     
     
         4 . The lubricating oil composition of  claim 1 , further comprising an ashless dispersant.  
     
     
         5 . The lubricating oil composition of  claim 4 , wherein said dispersant is a polyisobutenyl succinimide.  
     
     
         6 . The lubricating oil composition of  claim 1 , wherein said copper antioxidant is copper oleate.  
     
     
         7 . The lubricating oil composition of  claim 1 , wherein said oil of lubricating viscosity has a viscosity between 4.0 mm 2 /sec and 5.5 mm 2 /sec at 100° C.  
     
     
         8 . The lubricating oil composition of  claim 1 , wherein said oil of lubricating oil composition is a Group II oil, a Group III oil, a Group IV oil, a Group V oil or a mixture thereof, or is mixture of a Group I oil and at least one of a Group II oil, a Group III, a Group IV oil, or a Group V oil.  
     
     
         9 . The lubricating oil composition of  claim 1 , wherein said oil of lubricating viscosity comprises a Group IV oil.  
     
     
         10 . The composition of  claim 1 , wherein said molybdenum compound is an organo-molybdenum compound.  
     
     
         11 . The composition of  claim 10 , wherein said organo-molybdenum compound is molybdenum dithiocarbamate.  
     
     
         12 . A composition of  claim 1 , which composition is substantially free of ashless antioxidant.  
     
     
         13 . The composition of  claim 1 , further comprising at least one overbased metallic detergent.  
     
     
         14 . The composition of  claim 13 , wherein said at least one overbased metallic detergent is an overbased calcium detergent.  
     
     
         15 . A composition of  claim 1 , which composition contains no more than 0.5 wt. % of sulfur.