Lubricating compositions and methods of operating an internal combustion engine

Abstract

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.

1 . An internal combustion engine lubricating composition comprising:
 an oil of lubricating viscosity;   a boron-containing additive;   a boron-free polyisobutenyl succinimide dispersant;   an overbased magnesium-based detergent in an amount to deliver at least 300 ppm magnesium to the lubricating composition;   an overbased calcium-based detergent in an amount to deliver at least 400 ppm calcium to the lubricating composition; and   an ashless friction modifier,   wherein the lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 less than 2.7 mPa·s.   
     
     
         2 . The composition of  claim 1 , wherein the oil of lubricating viscosity includes at least 60 weight percent of a Group IV base oil. 
     
     
         3 . The lubricating composition according to  claim 1 , wherein the boron-containing additive is a boron-containing succinimide dispersant derived from a polyisobutylene having a vinylidene content of greater than 70 mol % and a polyolefin having a number average molecular weight of from 1750 to 2200. 
     
     
         4 .- 5 . (canceled) 
     
     
         6 . The lubricating composition according to  claim 1 , wherein the boron-containing succinimide dispersant is present in the lubricating composition in an amount of from 0.2 to 2.1 wt %. 
     
     
         7 .- 9 . (canceled) 
     
     
         10 . The lubricating composition according to  claim 1 , wherein the boron-free polyisobutenyl succinimide dispersant has a number average molecular weight of from 750 to 2500 and is present in the lubricating composition in an amount 0.5 to 6.5 wt %. 
     
     
         11 .- 15 . (canceled) 
     
     
         16 . The lubricating composition according to  claim 1 , wherein the boron-free polyisobutenyl succinimide dispersant includes a first boron-free polyisobutenyl succinimide dispersant having a number average molecular weight of from 750 to 1750 and is present in the lubricating composition in an amount of from 0.5 to 4.5 and a second boron-free polyisobutenyl succinimide dispersant having a number average molecular weight of from 1950 to 2500 and is present in the lubricating composition in an amount of from 0.2 to 2.0. 
     
     
         17 .- 18 . (canceled) 
     
     
         19 . The lubricating composition according to  claim 1 , wherein the overbased magnesium-based detergent is an overbased alkylbenzene sulfonate detergent having a metal ratio of at least 8 and a TBN (KOH/g) greater than 200 and present in the lubricating composition in an amount of from 0.1 to 1.5 wt %. 
     
     
         20 .- 25 . (canceled) 
     
     
         26 . The lubricating composition according to  claim 1 , wherein the overbased magnesium-based detergent delivers from 300 to 800 ppm magnesium to the lubricating composition. 
     
     
         27 .- 28 . (canceled) 
     
     
         29 . The lubricating composition according to  claim 1 , wherein the overbased calcium-based detergent is present in the lubricating composition in an amount of from 0.1 to 2.5 wt %. 
     
     
         30 .- 31 . (canceled) 
     
     
         32 . The lubricating composition according to  claim 1 , wherein the overbased calcium-based detergent has a metal ratio of at least 5 and a TBN (KOH/g) of from 100 to 550. 
     
     
         33 .- 34 . (canceled) 
     
     
         35 . The lubricating composition according to  claim 1 , wherein the overbased calcium-based detergent delivers from 750 to 1200 ppm calcium to the lubricating composition. 
     
     
         36 . (canceled) 
     
     
         37 . The lubricating composition according to  claim 1 , wherein the overbased calcium-based detergent is selected from an overbased calcium salixarate detergent, an overbased calcium salicylate detergent, or mixtures thereof. 
     
     
         38 .- 39 . (canceled) 
     
     
         40 . The lubricating composition according to  claim 1 , further comprising an ashless antioxidant present in the lubricating composition in an amount of from 0.2 to 2.1 wt %. 
     
     
         41 .- 42 . (canceled) 
     
     
         43 . The lubricating composition according to  claim 1 , wherein the ashless friction modifier is an ethoxylated amine selected from an ethoxylated tallow amine and ethoxylated oleyl amide. 
     
     
         44 .- 47 . (canceled) 
     
     
         48 . The lubricating composition according to  claim 1 , further comprising a zinc dialkyldithiophosphate anti-wear agent in an amount to deliver 200 ppm up to 1000 ppm phosphorus to the lubricating composition. 
     
     
         49 .- 51 . (canceled) 
     
     
         52 . The lubricating composition according to  claim 1 , further comprising an oxyalkylated hydrocarbyl phenol represented by the following formula: 
       
         
           
           
               
               
           
         
         wherein each R 2  is independently hydrogen or a hydrocarbyl group of 1 to 6 carbon atoms; 
         R 3  is hydrogen, a hydrocarbyl group of 1 to 24 carbon atoms, or an acyl group represented by —C(═O)R 5 ; 
         R 5  is a hydrocarbyl group of 1 to 24 carbon atoms; 
         R 4  is a polyisobutenyl group having a number average molecular weight of 550 to 2300; and 
         n=1 to 10, 
       
       where the oxyalkylated hydrocarbyl phenol is present in the lubricating composition in an amount ranging from 0.01 wt % to 5 wt %. 
     
     
         53 .- 54 . (canceled) 
     
     
         55 . The lubricating composition according to  claim 1 , wherein the lubricating composition has an HTHS less than 2.5. 
     
     
         56 .- 58 . (canceled) 
     
     
         59 . The lubricating composition according to  claim 1 , wherein the lubricating composition has an HTHS of between 1.8 and 2.2 and a Noack volatility of 13 wt % to 20 wt % according to one or more of ASTM D5800 and CED L-40-93. 
     
     
         60 . (canceled) 
     
     
         61 . A method of method of lubricating an internal combustion engine comprising supplying to the internal combustion engine a lubricating composition according to  claim 1 . 
     
     
         62 .- 63 . (canceled)