Lubricating composition

Abstract

A lubricating oil composition comprising: (a) a base oil composition comprising Fischer-Tropsch derived base oil; and (b) an organic molybdenum compound; (c) 30 wt % or less solvency booster; (d) antioxidant selected from aminic antioxidants, phenolic antioxidants, and mixtures thereof; (e) detergent comprising alkaline earth metal salicylate. The lubricating oil composition of the present invention provides improved anti-wear properties, as well as improved oxidation and improved piston cleanliness properties.

1 . A lubricating oil composition comprising:
 (a) a base oil composition comprising a Fischer-Tropsch derived base oil; and   (b) an organic molybdenum compound;   (c) 30 wt % or less solvency booster;   (d) antioxidant selected from aminic antioxidants, phenolic antioxidants, and mixtures thereof;   (e) detergent comprising alkaline earth metal salicylate.   
     
     
         2 . A lubricating oil composition according to  claim 1  wherein the organic molybdenum compound is a sulphur-containing organic molybdenum compound. 
     
     
         3 . A lubricating oil composition according to  claim 2  wherein the sulphur-containing organic molybdenum compound is selected from molybdenum dithiophosphate, molybdenum dithiocarbamate and mixtures thereof. 
     
     
         4 . A lubricating oil composition according to any of  claims 1  to  3  wherein the detergent comprises (i) an alkaline earth metal salicylate having a TBNE (total base number equivalent, as determined by ASTM D2896) in the range of from 50 to 150; (ii) an alkaline earth metal salicylate having a TBNE in the range of from 150 to 250; and (iii) an alkaline earth metal salicylate having a TBNE in the range of from 250 to 400. 
     
     
         5 . A lubricating oil composition according to any of  claims 1  to  4  wherein the solvency booster is selected from alkylated naphthalenes, alkyl benzenes, naphthenics, esters, and mixtures thereof. 
     
     
         6 . A lubricating oil composition according to any of  claims 1  to  5  wherein the solvency booster is present at a level of from 1 wt % to 20 wt %, by weight of the lubricant composition. 
     
     
         7 . A lubricating oil composition according to any of  claims 1  to  6 , wherein the antioxidant is an aminic antioxidant, preferably a diphenylamine. 
     
     
         8 . A lubricating oil composition according to any of  claims 1  to  7  wherein the alkaline earth metal salicylates are calcium salicylates. 
     
     
         9 . A lubricating oil composition according to any of  claims 1  to  8  comprising one or more zinc-based anti-wear additives. 
     
     
         10 . A lubricating oil composition according to any of  claims 1  to  9  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. of from 1 mm 2 /s to 35 mm 2 /s. 
     
     
         11 . Use of a lubricating oil composition according to any of  claims 1  to  10  for providing improved anti-wear properties, in particular as determined by the HFRR or the ASTM G133 sliding wear test method.