Engine oil compositions
AssigneeNippon Mitsubishi Oil Corporation
InventorsIsao Kurihara, Jinichi Igarashi, Kiyoshi Inoue
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AssigneeNippon Mitsubishi Oil Corporation
InventorsIsao Kurihara, Jinichi Igarashi, Kiyoshi Inoue
Estimating the term…
Engine oil compositions are provided containing (A) a lubricating base oil having a kinematic viscosity at 100° C. of 3 to 6 mm2/S, a viscosity index of 120 or more, and a total aromatic content of 5 percent by mass or less and (B) a polymethacrylate-based viscosity index improver, preferably having a weight average molecular weight of 180,000 or more, (A) and (B) being blended in such an amount that the composition has a kinematic viscosity at 100° C. of 4.0 to 9.3 mm2/s. The engine oil compositions may also contain a molybdenumdithiocarbamate, as well as one or more other engine oil additives. The engine oil compositions preferably have a high-temperature, high shear viscosity at 150° C. of 2.4 to 2.7 mPa·s, a NOACK evaporation loss of 16 percent by mass or less, and a CCS viscosity at −25° C. of 3500 mPa·s or less.
An engine oil composition consisting essentially of (A) a lubricating base oil having a kinematic viscosity at 100° C. of 3 to 6 mm2/s, a viscosity index of 120 or more, and a total aromatic content of 5 percent by mass or less and (B) a polymethacrylate-based viscosity index improver having a weight-average molecular weight of 180,000 or more, (A) and (B) being blended in such amounts that the composition has a kinematic viscosity at 100° C. of 4.0 to 9.3 mm2/s and a high temperature, high shear viscosity at 150° C. of 2.4 to 2.7 mPa·s.
An engine oil composition consisting essentially of (A) a lubricating base oil having a kinematic viscosity at 100° C. of 3 to 6 mm2/s, a viscosity index of 120 or more, and a total aromatic content of 5 percent by mass or less and (B) a polymethacrylate-based viscosity index improver having a weight-average molecular weight of 180,000 or more, (A) and (B) being blended in such amounts that the composition has a kinematic viscosity at 100° C. of 4.0 to 9.3 mm2/s and a high temperature high shear viscosity at 150° C. of 2.4 to 2.7 mPa·s, and (C) a molybdenumdithiocarbamate.
Dependencies are inferred from the claim text.