The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.

A lubricating oil composition and method for controlling timing chain stretch, wherein the composition contains greater than 50 wt. % of base oil, zinc dialkyl dithiophosphate(s) to provide 350-2200 ppm zinc, molybdenum-containing compound(s) to provide >1-3000 ppm molybdenum, and magnesium-containing detergent(s) to provide <2050 ppm magnesium, all based on the total weight of the composition. The composition has a total TBN of less than 7.5 mg KOH/g, measured by ASTM D-2896 and a weight ratio of ppm of zinc from zinc dialkyl dithiophosphate(s) to ppm of molybdenum from molybdenum-containing compound(s) of <10. The method employs the lubricating oil composition to control timing chain stretch to a level of 0.1% or less.

A lubricating oil composition and method for controlling timing chain stretch, wherein the composition contains greater than 50 wt. % of base oil, zinc dialkyl dithiophosphate(s) to provide 350-2200 ppm zinc, molybdenum-containing compound(s) to provide >1-3000 ppm molybdenum, and magnesium-containing detergent(s) to provide <2050 ppm magnesium, all based on the total weight of the composition. The composition has a total TBN of less than 7.5 mg KOH/g, measured by ASTM D-2896 and a weight ratio of ppm of zinc from zinc dialkyl dithiophosphate(s) to ppm of molybdenum from molybdenum-containing compound(s) of <10. The method employs the lubricating oil composition to control timing chain stretch to a level of 0.1% or less.

A lubricating oil composition including: a lubricant base oil; (A) a triazole metal deactivator in an amount of 0.005 to 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition; and (B1) a succinimide compound represented by the following general formula (1) in an amount of 0.0005 to 0.02 mass % in terms of nitrogen on the basis of the total mass of the composition: ##STR00001##
wherein in the general formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-36 linear or branched chain alkyl or alkenyl group, and at least one of R.sup.1 and R.sup.2 is a C8-36 linear or branched chain alkyl or alkenyl group, and n represents an integer of 1 to 10.

A lubricating oil composition including: a lubricant base oil; (A) a triazole metal deactivator in an amount of 0.005 to 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition; and (B1) a succinimide compound represented by the following general formula (1) in an amount of 0.0005 to 0.02 mass % in terms of nitrogen on the basis of the total mass of the composition: ##STR00001##
wherein in the general formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-36 linear or branched chain alkyl or alkenyl group, and at least one of R.sup.1 and R.sup.2 is a C8-36 linear or branched chain alkyl or alkenyl group, and n represents an integer of 1 to 10.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.