Abstract: To provide a fuel-efficient lubricating oil composition, particularly suitable for internal combustion engines, which has a reduced shear viscosity in an intermediate temperature range from 80 to 100° C., an effective temperature range for reducing fuel consumption. The present invention provides a lubricating oil composition comprising a base oil incorporated with a viscosity index improver, wherein the viscosity index improver has a peak area at a chemical shift between 3.4 and 3.7 ppm in a spectral pattern observed by nuclear magnetic resonance analysis (1H-NMR) accounts for 5% or more of the total peak area.

Abstract: An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard (SAE (Society of Automotive Engineers) viscosity classification) and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of anti-abrasion agent, said engine oil composition characterized by the following facts: the engine oil composition contains 0.02-0.12 mass % of zinc dithiophosphate, measured in the phosphorous amount based on the total weight of the composition, in a base oil compromised of a mineral oil and/or a synthetic oil; (1) the high-temperature high-shear viscosity at 150° C. and at a shear rate of 1×106 s?1 is less than 2.6 mPa·s; (2) the engine oil composition satisfies the following equation: kinematic ? ? viscosity ? ? at ? ? 100 ? ? ? C .

Abstract: To provide a fuel-efficient lubricating oil composition, particularly suitable for internal combustion engines, which has a reduced shear viscosity in an intermediate temperature range from 80 to 100° C., an effective temperature range for reducing fuel consumption. The present invention provides a lubricating oil composition comprising a base oil incorporated with a viscosity index improver, wherein the viscosity index improver has a peak area at a chemical shift between 3.4 and 3.7 ppm in a spectral pattern observed by nuclear magnetic resonance analysis (1H-NMR) accounts for 5% or more of the total peak area.

Abstract: An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard (SAE (Society of Automotive Engineers) viscosity classification) and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of anti-abrasion agent, said engine oil composition characterized by the following facts: the engine oil composition contains 0.02-0.12 mass % of zinc dithiophosphate, measured in the phosphorous amount based on the total weight of the composition, in a base oil compromised of a mineral oil and/or a synthetic oil; (1) the high-temperature high-shear viscosity at 150° C. and at a shear rate of 1×106 s?1 is less than 2.6 mPa.