Branched diesters for use to reduce the fuel consumption of an engine

Abstract

The invention refers to use of lubricant compositions comprising a specific diester and additives to reduce the fuel consumption of an engine.

1 . Method of reducing the fuel consumption of an engine, comprising:
 Administering a lubricant composition comprising at least one compound of formula (I) below and at least one lubricant additive chosen from the list consisting of detergent additives, anti-wear additives, friction modifiers additives, extreme pressure additives, antioxidant additives, dispersing agents, pour-point depressant additives, anti-foam agents, thickeners, viscosity index improvers and mixtures of two or more thereof, to an engine,   
       
         
           
           
               
               
           
         
       
       wherein:
 n is below 1.1 
 R1 represents a linear or branched, saturated or unsaturated C3-C20, 
 R′ represents a linear or branched, saturated or unsaturated C2-C1 6, 
 R represents a linear or branched, saturated or unsaturated C1-C20. 
 
     
     
         2 . Method according to  claim 1 , wherein in the formula (I):
 n is 1;   the total amount of carbon atoms being more than 15 and less than 40.   
     
     
         3 . Method according according to  claim 1 , wherein in the formula (I),
 R1 represents a linear or branched, saturated or unsaturated C5-C15 alkyl group;   R′ represents a linear or branched, saturated or unsaturated C3-C8 alkyl group; R represents a linear or branched, saturated or unsaturated C1-C15 alkyl group.   
     
     
         4 . Method according according to  claim 1 , wherein in the formula (I),
 R1 represents a saturated linear C5-C15 alkyl group, more preferably a saturated linear C5-C12 alkyl group;   R′ represents a saturated linear C3-C8 alkyl group, more preferably a saturated linear C5-C8 alkyl group;   R represents a saturated linear or branched C5-C15 alkyl group, more preferably a saturated linear or branched C5-C10 alkyl group.   
     
     
         5 . Method according according to  claim 1 , wherein in the formula (I),
 R1 represents a saturated linear C5-C10 alkyl group, more preferably a saturated linear C5-C8 alkyl group;   R′ represents a saturated linear C5-C8 alkyl group;   R represents a saturated, linear or branched C5-C10 alkyl group, preferably a saturated linear C5-C10 alkyl group.   
     
     
         6 . Method according to  claim 5 , wherein the compound of formula (I) is a compound of formula (Ia) 
       
         
           
           
               
               
           
         
       
     
     
         7 . Method according to  claim 1 , wherein in the formula (I):
 R1 represents a saturated linear or branched C5-C15 alkyl group, more preferably a saturated linear C8-C12 alkyl group;   R′ represents a saturated linear C5-C8 alkyl group;   R represents a saturated, linear or branched C5-C10 alkyl group, preferably a saturated branched C5-C10 alkyl group.   
     
     
         8 . Method according to  claim 7 , wherein the compound of formula (I) is a compound of formula (Ib) 
       
         
           
           
               
               
           
         
       
     
     
         9 . Method according to  claim 1 , wherein the lubricant composition comprises from 0.1 to 50%, preferably from 1 to 50%, more preferably from 5 to 30% by weight based on the total weight of lubricant composition, of a compound of formula (I). 
     
     
         10 . Method according to  claim 1 , wherein the lubricant composition comprises further at least one lubricant base oil. 
     
     
         11 . Method according to  claim 1 , wherein the lubricant base oil is a group III lubricant base oil. 
     
     
         12 . Method according to  claim 1 , wherein the lubricant composition comprises from 50 to 99%, preferably from 50 to 80% by weight on the total weight of lubricant composition, of a lubricant base oil. 
     
     
         13 . Method according to  claim 1 , wherein the additive is at least one viscosity index improver, preferably at least one polymeric viscosity index improver, more preferably chosen among: polyacrylates and polymethacrylates,
 olefin homopolymers or copolymers, preferably ethylene/propylene   styrene copolymers, preferably with isoprene or a diene such as butadiene, hydrogenated or not, isoprene polymers, preferably radial hydrogenated polyisoprene,   esterified polystyrenes, preferably esterified poly(styrene-co-maleic anhydride) mixtures of two or more of the above   
     
     
         14 . Method according to  claim 1  to further improve the cleanliness of an engine, preferably of a car engine, more preferably of at least one piston of a car engine.