The present disclosure provides a lubricating oil composition which is excellent in metal fatigue life, wear resistance and electrical insulating properties, even when the composition has a reduced viscosity. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof; and (C) at least one selected from a phosphorus-based anti-wear agent and a phosphorus-based extreme pressure agent, the at least one agent being contained in such an amount that the content of phosphorus is from 50 to 500 ppm by weight based on the total weight of the lubricating oil composition.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.

The present disclosure provides a lubricating oil composition which has a viscosity much lower than that of a conventional lubricating oil composition, and which is excellent in metal fatigue life, wear resistance and electrical insulating properties. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; and (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof. The above described lubricating oil composition does not comprise a viscosity index improver, and has a kinematic viscosity at 100 C. of not less than 1 and less than 5 mm.sup.2/s.

The disclosed technology relates to hydroxy functionalized ashless additives useful in engine oil compositions due to their ability to reduce deposits, particularly deposits seen in turbocharged direct injection (TDI) engines. The described additives include ashless saturated compounds having a long chain hydrocarbyl polymer terminated by a hydroxyl group. The disclosed technology also relates to lubricant compositions containing the described additives, processes of making the described additives, and methods of using the described additives.

The disclosed technology relates to hydroxy functionalized ashless additives useful in engine oil compositions due to their ability to reduce deposits, particularly deposits seen in turbocharged direct injection (TDI) engines. The described additives include ashless saturated compounds having a long chain hydrocarbyl polymer terminated by a hydroxyl group. The disclosed technology also relates to lubricant compositions containing the described additives, processes of making the described additives, and methods of using the described additives.

The disclosed technology relates to hydroxy functionalized ashless additives useful in engine oil compositions due to their ability to reduce deposits, particularly deposits seen in turbocharged direct injection (TDI) engines. The described additives include ashless saturated compounds having a long chain hydrocarbyl polymer terminated by a hydroxyl group. The disclosed technology also relates to lubricant compositions containing the described additives, processes of making the described additives, and methods of using the described additives.