Provided are a lubricating oil composition containing a mineral oil (1) having a kinematic viscosity at 100 C. of 2 mm.sup.2/s or more and less than 2.5 mm.sup.2/s, and a polymethacrylate (2) having a functional group containing an oxygen atom in the molecule while having a specific structural, unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.

Provided is a lubricating oil composition, which has low viscosity but also prolonged anti-shudder life without reduction of intermetallic friction coefficient. The lubricating oil composition is characterized in comprising (A) a lubricating base oil, and (C) (C-1) a borated succinimide compound with a mass average molecular weight of 4,000-7,000 and (C-2) a borated succinimide compound with a mass average molecular weight of greater than 7,000-10,000.

Provided are bimodal copolymer compositions, and in particular bimodal ethylene--olefin copolymer compositions. The copolymer compositions comprise first and second ethylene--olefin copolymer components. The bimodal compositions are particularly useful as viscosity or rheology modifiers, e.g., in lubricating oil compositions. Lubricating oil compositions comprising the copolymer compositions advantageously exhibit enhanced shear stability index (SSI) and thickening efficiency (TE) values, while maintaining excellent low-temperature properties such as Pour Point, mini-rotary viscometer viscosity, and cold crank simulation performance. Also provided are methods of tuning or adjusting TE and/or SSI of bimodal copolymer compositions, especially ethylene copolymer compositions, by adjusting melt flow rate (MFR), corrected melt flow rate ratio (cMFRR), and/or intra-fractional melt flow rate ratio (IFMFRR) of the copolymer composition in order to obtain an adjusted copolymer composition exhibiting adjusted TE and/or SSI. Such methods provide excellent flexibility in rheology modifier production campaigns targeting different TE and/or SSI values.

This application relates to copolymer compositions and copolymerization processes. The processes may use two different metallocene catalysts: one capable of producing high molecular weight copolymers; and one suitable for producing lower molecular weight copolymers having at least a portion of vinyl terminations, and the copolymer compositions produced thereby. Copolymer compositions may comprise (1) a first ethylene copolymer fraction having high molecular weight, exhibiting branching topology, and having relatively lower ethylene content (based on the weight of the first ethylene copolymer fraction); and (2) a second ethylene copolymer fraction having low molecular weight, exhibiting linear rheology, and having relatively higher ethylene content (based on the weight of the second ethylene copolymer fraction). It is believed that the unique combination of these properties provides a copolymer composition with advantageous viscosity modifying properties, such as an excellent combination of shear thinning and fuel economy, as well as high thickening efficiency.

The invention relates to the field of lubricants and provides a lubricating composition comprising at least one base oil, the kinematic viscosity of which measured at 40 C. does not exceed 10 mm.sup.2/s and the pour point of which does not exceed 50 C., and at least one thickener, said lubricating composition having a pour point not exceeding 55 C.

Provided are a lubricating oil composition containing a synthetic oil (1) having a kinematic viscosity at 100 C. of 2.5 mm.sup.2/s or less, and a polymethacrylate (2) having a monovalent functional group containing an oxygen atom in the molecule while having a specific structural unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.

Provided are a lubricating oil composition containing a mineral oil (1) having a kinematic viscosity at 100 C. of 2.5 mm.sup.2/s or more and 5 mm.sup.2/s or less, and a polymethacrylate (2) having a functional group containing an oxygen atom in the molecule while having a specific structural unit, which satisfies both high viscosity index and high shear stability, and a lubrication method and a transmission using the lubricating oil composition.

A lubricating fluid suitable for use as a shock absorber fluid is disclosed. The lubricating fluid comprises at least 40 wt %, based upon the weight of the lubricating fluid, of a GTL base oil, has a viscosity index in the range of from 50 to 1000, and a pour point of below 30 C.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.