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.

The invention relates to a food-grade high-temperature lubricant, more particularly a high-temperature oil and a high-temperature grease, comprising the following components: a) at least one oil selected from a trimellitic ester or a mixture of different trimellitic esters, alkylaromatics, preferably an aliphatically substituted naphthalene, or estolides; b) a hydrogenated or fully hydrogenated polyisobutylene or a mixture of hydrogenated or fully hydrogenated polyisobutylene; and c) additives individually or in combination.

In the case of the high-temperature grease, a thickener is added.

A urea grease of the invention is prepared by applying shear at a shear rate of 10.sup.2 s.sup.−1 or more to a mixture solution of an amine mixture containing an alicyclic monoamine and a chain aliphatic monoamine, and a diisocyanate compound to cause a reaction in the mixture, in which the urea grease has Peak High32-64s of 1.5 or less and Level High32-64s of 10 or less according to an FAG method.

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.

To provide a grease composition for a tapered roller bearing having superior bearing lifetime under a condition of high temperature and a condition of high load, and a tapered roller bearing in which the grease composition for the tapered roller bearing is filled. A tapered roller bearing 11 includes an inner ring 12 having a raceway surface 12a, an outer ring 13 having a raceway surface 13a and a plurality of tapered rollers 14, and a flange part of the inner ring 12 gets into sliding contact with the tapered rollers 14. Grease 16 is filled around the tapered rollers 14. The grease 16 includes a base oil, a thickener and an additive. A frequency in which a storage modulus, which varies depending on frequency, of the grease 16 becomes minimum is equal to 7 Hz or more.

In a fluid bearing lubricating oil, a viscosity index improver including polymethacrylate is added to an ester oil-based base oil.

Provided are a lubricating oil composition containing (A) a specific amide compound and (B) a metal-based detergent, wherein the content of the metal-based detergent (B) as converted in terms of metal atom is, based on the total amount of the composition, more than 300 ppm by mass and 1,000 ppm by mass or less, and having a high intermetallic friction coefficient and excellent clutch anti-shudder performance; and a lubrication method and a transmission using the composition.

The present invention provides a compound represented by formula (1) (in formula (1), R.sup.1 and R.sup.2 each independently represent a group represented by formula (2) or NHR.sup.0 (where R.sup.1 and R.sup.2 are not simultaneously NHR.sup.0), R.sup.0 represents any one of hydrogen, an alkyl group having 1-20 carbon atoms, an alkenyl group having 2-30 carbon atoms, an aryl group having 6-30 carbon atoms, an alkylaryl group having 7-30 carbon atoms, and an arylalkyl group having 7-30 carbon atoms, each R.sup.3 independently represents hydrogen or a hydrocarbon group having 1-30 carbon atoms, l represents an integer of 0-4, m represents an integer of 1-4 (where m is an integer of 2-4 in the case where R.sup.1 and R.sup.2 are a group represented by formula (2)), and each n independently represents an integer of 0-4, and, in formula (2), R.sup.4 represents a hydrocarbon group having 6-24 carbon atoms, and X.sup.1 and X.sup.2 each independently represent an oxygen atom or a sulfur atom). ##STR00001##

The present invention addresses a problem of providing a grease composition containing a urea-based thickener and capable of appropriately maintaining the kinematic friction force in lubrication parts. The grease composition contains a base oil (A) and a urea-based thickener (B), wherein the base oil (A) has a kinematic viscosity at 40° C. of 100 mm.sup.2/s or more, and the particles containing the urea-based thickener (B) in the grease composition satisfy the following requirement (I). Requirement (I): the area-based arithmetic average particle diameter of the particles is 2.0 μm or less, as measured by a laser diffraction/scattering method.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and a metal overbased detergent. The metal overbased detergent may be selected from sulfonate detergents, phenate detergents, and salicylate detergents, especially sulfonate detergents with a metal ratio of at least 5.