This disclosure relates to grease compositions having at least one base oil, at least one soap or non-soap thickener, and at least one elastomeric triblock copolymer of the general configuration A-B-A, in which A is a relatively hydrophobic polymer block and B is a relatively hydrophilic polymer block, and in which A forms less than 50% by weight of the total molecular weight of the elastomeric triblock copolymer. When the grease compositions are used under high shear conditions, structural stability and resistance to breaking down in accordance with ASTM D7342 is improved. When the grease compositions are used in low temperature conditions, low temperature starting and running torque in accordance with ASTM D1478 is improved.

The present invention is directed to a lubricating oil additive containing a vicinal diol and a particular detergent blend typically is low viscosity base oils whereby exhibiting improved fuel economy. In this respect, disclosed is a lubricating oil composition comprising: a major amount of base oil of lubricating viscosity; a friction modifier which is selected from the group consisting of C.sub.10-C.sub.30 alkane 1,2-diols and C.sub.10-C.sub.30 alkene 1,2-diols; an overbased alkyl alkaline earth metal hydroxybenzoate detergent having a metal ratio less than 3.0; and an overbased alkyl calcium sulfonate or an overbased alkyl calcium hydroxybenzoate having a metal ratio of 3.5 or greater.

An object of the present invention is to provide a lubricating oil composition particularly excellent in viscosity characteristics at a low temperature. The present invention provides: a lubricating oil composition including a polymer (A) and a base oil (B), wherein the polymer (A) satisfies the following requirement (A-1), and the content ratio of the polymer (A) and the base oil (B) is such that the ratio of a resin (A) is within the range of from 0.1 to 50 parts by mass with respect to 100 parts by mass of the total amount of the polymer (A) and the base oil (B). (A-1) The polymer (A) is a polymer containing a structural unit derived from an -olefin having 20 or less carbon atoms.

A comb polymer can be used for reducing a Noack evaporation loss of a lubricant composition, especially of an engine oil composition. Application of the comb polymer to the lubricant composition can bring about the desired reduction. The comb polymer can include specified amounts of macromonomer and alkyl acrylates. Resulting lubricant compositions can include the comb polymer.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

A viscosity index improver containing a copolymer (A) whose essential constituent monomer is a monomer (a) having a number average molecular weight of 800 to 4,000 represented by the following formula (1), the copolymer (A) having a solubility parameter in the range of 9.00 to 9.40:

##STR00001##

wherein R.sup.1 is a hydrogen atom or a methyl group; X.sup.1 is a group represented by O, O(AO).sub.m, or NH, AO is a C2-C4 alkyleneoxy group, m is an integer of 1 to 10, each AO may be the same or different when m is 2 or more, and the (AO).sub.m moieties may be randomly bonded or block-bonded; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer whose essential constituent monomer is butadiene in which the butadiene is present in a proportion of 50% by weight or more based on the weight of R.sup.2, or after removal of one hydrogen atom from a polymer formed by partial hydrogenation of the hydrocarbon polymer; and p represents a number of 0 or 1.

The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

Provided is a lubricating oil composition containing a base oil (A) and a viscosity index improver (B) and satisfying the following requirements (I) and (II):

Requirement (I): a kinematic viscosity at 80 C., V.sub.80 of the lubricating oil composition is 11.5 mm.sup.2/s or less;

Requirement (II): a ratio [V.sub.80/T.sub.80] of a kinematic viscosity at 80 C., V.sub.80 (m.sup.2/s) to an oil film thickness measured at a sliding speed of 2.0 m/s, a maximum Hertz pressure of 0.8 GPa, and an oil temperature of 80 C., T.sub.80 (nm) of the lubricating oil composition is less than 0.105 ((m.sup.2/s)/nm).

The lubricating oil composition is excellent in fuel saving properties and anti-wear properties even when it is used in a temperature environment of around 80 C. which is assumed to fall within a range where an engine is practically used.

A lubricating oil composition comprising greater than 50 wt. % of a base oil of lubricating viscosity, and an additive composition comprising: an amount of one or more zinc dialkyl dithiophosphates (ZDDP compounds) and an amount of one or more viscosity modifiers, wherein an amount of phosphorus (P) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds divided by the amount of the one or more viscosity modifiers (VM) in weight percent based on a total weight of the lubricating oil composition is a P/VM quotient of more than about 0.0075. The lubricating oil composition can improve resistance to engine deposits and extend oil drain intervals of an internal combustion engine.

Provided are: a lubricating oil composition satisfying both high viscosity index and high shear stability, which contains a base oil having a kinematic viscosity at 40 C. of 4.0 mm.sup.2/s or more and less than 6.0 mm.sup.2/s, a kinematic viscosity at 100 C. of 1.0 mm.sup.2/s or more and less than 2.0 mm.sup.2/s, and a flash point of 140 C. or higher, and a polymethacrylate having a specific structure; and a lubrication method and a transmission each using the lubricating oil composition.