| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a lubricant composition imparting fuel consumption saving performance. <P>SOLUTION: The lubricant composition includes: a lubricant base oil having dynamic viscosity at 100°C of 1-6 mm<SP>2</SP>/s, %C<SB>P</SB>of≥70, and %C<SB>A</SB>of≤2; a first viscosity index improver having PSSI (Permanent Shear Stability Index) of≤30 which gives the ratio of viscosity improvement effect (A) of formula (1) to viscosity improvement effect (B) of formula (2) (A/B) of≥4.5 when added to the lubricant base oil; and a second viscosity index improver which gives the ratio A/B of <4.5 when added to the lubricant base oil; wherein A=X-X<SB>0</SB>(1); B=Y-Y<SB>0</SB>(2), in which A is viscosity improvement effect in dynamic viscosity at 100°C, B is viscosity improvement effect in HTHS (High Temperature High Shear Viscosity) viscosity at 150°C, X is dynamic viscosity at 100°C of a mixture including a lubricant base oil and 3 mass% of a first or second viscosity index improver, X<SB>0</SB>is dynamic viscosity at 100°C of a lubricant base oil, Y is HTHS viscosity at 150°C of a mixture including a lubricant base oil and 3 mass% of a first or second viscosity index improver, and Y<SB>0</SB>is HTHS viscosity at 150°C of a lubricant base oil. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
