Manual transmission oil composition having enhanced fuel efficiency and low viscosity

Abstract

Disclosed is a manual transmission oil composition which include: (A) a polyalphaolefin (PAO) synthetic base oil in an amount of about 75 to 85 wt %; (B) an ester-based viscosity modifier in an amount of about 3 to 10 wt %; and (C) an additive in an amount of about 8 to 15 wt % which includes one or more of an anti-wear agent, a detergent dispersant, a friction modifier, an extreme pressure additive, and an anti-oxidant, based on the total weight of the manual transmission oil composition. Accordingly, the manual transmission oil composition may have a low viscosity as compared to conventional manual transmission oils, and may provide improvements in endurance of a transmission, reduction in a Rattle noise, and further improvement in fuel efficiency of vehicles by about 1 to 2%.

What is claimed is: 
     
         1 . A manual transmission oil composition comprising:
 a polyalphaolefin (PAO) synthetic base oil in an amount of about 75 to 85 wt % based on the total weight of the manual transmission oil composition;   an ester-based viscosity modifier in an amount of about 3 to 10 wt % based on the total weight of the manual transmission oil composition; and   an additive in an amount of about 8 to 15 wt % based on the total weight of the manual transmission oil composition,   wherein the additive comprises one or more selected from an anti-wear agent, a detergent dispersant, a friction modifier, an extreme pressure additive, and an anti-oxidant.   
     
     
         2 . The manual transmission oil composition of  claim 1 , wherein the ester-based viscosity modifier is a hybrid olefin ester-based copolymer having a backbone including units derived from a C 6  or more α-olefin monomer and an ethylenically unsaturated carboxylic acid or derivatives thereof. 
     
     
         3 . The manual transmission oil composition of  claim 1 , wherein the manual transmission oil composition further comprises polyalkyl methacrylate in an amount of about 3 to 5 wt % as the viscosity modifier. 
     
     
         4 . The manual transmission oil composition of  claim 3 , wherein the polyalkyl methacrylate has a number average molecular weight of about 300,000 to 400,000 and about four to six C 12  to C 15  polymer chains. 
     
     
         5 . A manual transmission oil of  claim 1 , wherein the manual transmission oil has an average kinematic viscosity of about 5 to 6 cSt at a temperature of about 100° C., an average kinematic viscosity of about 24 to 30 cSt at a temperature of about 40° C., and an average absolute viscosity of about 4,000 to 10,000 cP at a temperature of about −40° C. 
     
     
         6 . A manual transmission oil of  claim 1  which consists essentially of the polyalphaolefin (PAO) synthetic base oil; ester-based viscosity modifier; and additive. 
     
     
         7 . A manual transmission oil of  claim 1  which consists of the polyalphaolefin (PAO) synthetic base oil; ester-based viscosity modifier; and additive. 
     
     
         8 . A vehicle that comprises a manual transmission oil of  claim 1 .