The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Nov. 04, 2003

Filed:

Dec. 12, 2002
Applicant:
Inventors:

Isao Kurihara, Yokohama, JP;

Jinichi Igarashi, Yokohama, JP;

Kiyoshi Inoue, Yokohama, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C10M / ; C10M / ;
U.S. Cl.
CPC ...
C10M / ; C10M / ;
Abstract

Engine oil compositions are provided containing (A) a lubricating base oil having a kinematic viscosity at 100° C. of 3 to 6 mm /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 mm /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.


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