Lubricating oil composition for two-wheeled motor vehicles

Abstract

A lubricating oil composition for two-wheeled motor vehicles including a base oil and a metal phenate and having a coefficient of friction measured of less than 0.0900. The lubricating oil composition in which a performance required for lubricating oil for engines is satisfied, and a good shift feeling is achieved while a high coefficient of friction is kept in a wet clutch.

1 . A lubricating oil composition, comprising:
 a base oil; and   a metal phenate,   wherein the lubricating oil composition has a coefficient of friction of less than 0.0900 when measured with a disk of a standard test piece (AISI 52100) and a ¾ inch ball of the same material for 2 hours, with a load of 30 N, at a speed of 100 mm/s, at an oil temperature of 80° C., and with a slip-to-roll ratio (SRR) of 50%.   
     
     
         2 . The lubricating oil composition of  claim 1 , wherein a content of a sulfur atom in the metal phenate is 1.00 to 8.00% by mass. 
     
     
         3 . The lubricating oil composition of  claim 1 , wherein the metal phenate is an overbased calcium phenate. 
     
     
         4 . The lubricating oil composition of  claim 1 , wherein a content of the metal phenate is 1.10% by mass or more and 2.00% by mass or less based on a whole amount of the lubricating oil composition. 
     
     
         5 . The lubricating oil composition of  claim 1 , further comprising:
 a viscosity index improver.   
     
     
         6 . The lubricating oil composition of  claim 1 , wherein a performance classification evaluated in accordance with a clutch friction characteristics test of JASO T903:2016 is MA2. 
     
     
         7 . A method for lubricating an engine and a transmission of a two-wheeled motor vehicle, comprising:
 applying the lubricating oil of  claim 1  to the engine and the transmission.   
     
     
         8 . A method for producing a lubricating oil composition, comprising:
 mixing a base oil and a metal phenate,   wherein a coefficient of friction of the lubricating oil is less than 0.0900 when measured with a disk of a standard test piece (AISI 52100) and a ¾ inch ball of the same material for 2 hours, with a load of 30 N, at a speed of 100 mm/s, at an oil temperature of 80° C., and with a slip-to-roll ratio (SRR) of 50%.