Disclosed herein are marine diesel cylinder lubricating oil compositions which comprises (a) a major amount of one or more Group II basestocks, and (b) a detergent composition comprising (i) one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a TBN of about 100 to about 250, and (ii) one or more high overbased alkyl aromatic sulfonic acids or salts thereof; wherein the aromatic moiety of the alkyl aromatic sulfonic acids or salts thereof contains no hydroxyl groups; and wherein the marine diesel cylinder lubricating oil composition has a TBN of about 5 to about 120.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

Provided is a lubricating oil composition having a HTHS viscosity at 150 C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at 20 C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100 C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents.

Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.

A method for improving wear protection, while maintaining or improving deposit control and cleanliness, in an engine or other mechanical component lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and one or more lubricating oil additives including at least one borated detergent, as a minor component. The at least one borated detergent comprises a borated alkaline earth metal sulfonate. The borated alkaline earth metal sulfonate is present in an amount sufficient to provide a total boron concentration of about 300 parts per million or greater in the formulated oil. Wear protection is improved, and deposit control and cleanliness are maintained or improved, as compared to wear protection, deposit control and cleanliness achieved using a lubricating oil containing a borated additive other than the at least one borated alkaline earth metal sulfonate.

A method for improving wear protection, while maintaining or improving deposit control and cleanliness, in an engine or other mechanical component lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and one or more lubricating oil additives including at least one borated detergent, as a minor component. The at least one borated detergent comprises a borated alkaline earth metal sulfonate. The borated alkaline earth metal sulfonate is present in an amount sufficient to provide a total boron concentration of about 300 parts per million or greater in the formulated oil. Wear protection is improved, and deposit control and cleanliness are maintained or improved, as compared to wear protection, deposit control and cleanliness achieved using a lubricating oil containing a borated additive other than the at least one borated alkaline earth metal sulfonate.

An automatic transmission oil composition includes 80 to 85 wt % of a base oil, 1 to 5 wt % of metallocene polyalphaolefin, 1 to 5 wt % of a detergent-dispersant, 0.01 to 0.03 wt % of a trinuclear molybdenum-based dialkyldithiocarbamate friction modifier, 3 to 10 wt % of a viscosity modifier, and 3 to 5 wt % of an anti-wear additive. The automatic transmission oil composition is prepared by mixing base oil with metallocene polyalphaolefin and a trinuclear molybdenum-based dialkyldithiocarbamate friction modifier at specific mixing ratios, whereby the dynamic friction coefficient can be maintained at an equivalent level and the metal friction coefficient can be reduced, thus improving the power transfer efficiency between transmission metals and fuel economy (an improvement of 1.5% or more), increasing durability, and minimizing energy loss.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricating oil detergent composition comprises an overbased calcium sulfonate and a low ash detergent, which low ash detergent is metal free and comprises the reaction product of an acidic organic compound such as an alkylated salicylic acid, a boron compound and an amine component.