A lubricating oil composition having a sulfated ash content of from greater than 1.0 wt. % to about 2.0 wt. %, a phosphorus content of from about 0.07 to about 0.12 wt. % and a sulfur content of 0.4 wt. % or less, the lubricating oil composition comprising: (a) an oil of lubricating viscosity in a major amount; (b) an overbased magnesium detergent, in an amount providing the lubricating oil composition with at least 600 ppm of magnesium; (c) a boron-containing compound, in an amount providing the lubricating oil composition with at least 250 ppm of boron; and (d) a molybdenum-containing compound, in an amount providing the lubricating oil composition with at least 50 ppm of molybdenum, wherein the composition has a B/Mo mass ratio in a range of 2 to 10 and a S/Mo mass ratio in a range of 10 to 25.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt. % of a base oil, one or more overbased calcium sulfonate detergent(s) and one or more overbased calcium phenate detergent(s). The calcium, boron, nitrogen, and amount of soap are maintained within certain ratios, and the total base number contribution from all detergents to the lubricating oil composition is less than 4.2 mg KOH/g of the lubricating oil composition, as measured by the method of ASTM D-2896. The lubricating oil composition and method may be effective to reduce low-speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to capable lubricating oil compositions.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt. % of a base oil, one or more overbased calcium sulfonate detergent(s) and one or more overbased calcium phenate detergent(s). The calcium, boron, nitrogen, and amount of soap are maintained within certain ratios, and the total base number contribution from all detergents to the lubricating oil composition is less than 4.2 mg KOH/g of the lubricating oil composition, as measured by the method of ASTM D-2896. The lubricating oil composition and method may be effective to reduce low-speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to capable lubricating oil compositions.

A lubricating oil composition and method of operating a boosted internal combustion engine with reduced low-speed pre-ignition events and corrosion resistance. The oil composition includes a base oil, one or more overbased calcium sulfonate detergents, one or more overbased calcium phenate detergents, and one or more overbased magnesium-containing detergents. A ratio of ppm of calcium to TBN of the oil composition is less than 170; a ratio of ppm of magnesium to total soap content in wt. % is greater than 700; and there are limited amounts of boron and molybdenum, and all weight percentages and ppm values being based on the total weight of the oil composition. The compositions give low LSPI ratios and pass the Ball Rust test.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil includes greater than 50 wt. % of a base oil, one or more overbased calcium-containing detergents, one or more overbased magnesium-containing detergents and one or more molybdenum compounds and leads to a more than 60% reduction in LSPI compared to the LSPI of a reference oil and passes the Ball Rust Test. The ratio of wt % calcium from the overbased detergents to wt. % of magnesium from the overbased detergents is less than 11.9. A ratio of total ppm of magnesium to total TBN of the lubricating oil in mg KOH/g is greater than 19. A ratio of the total ppm of calcium to the total TBN of the lubricating oil is less than 222. The oil and method may reduce low-speed pre-ignition events in a boosted internal combustion relative to commercially available lubricating oils.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil includes greater than 50 wt. % of a base oil, one or more overbased calcium-containing detergents, one or more overbased magnesium-containing detergents and one or more molybdenum compounds and leads to a more than 60% reduction in LSPI compared to the LSPI of a reference oil and passes the Ball Rust Test. The ratio of wt % calcium from the overbased detergents to wt. % of magnesium from the overbased detergents is less than 11.9. A ratio of total ppm of magnesium to total TBN of the lubricating oil in mg KOH/g is greater than 19. A ratio of the total ppm of calcium to the total TBN of the lubricating oil is less than 222. The oil and method may reduce low-speed pre-ignition events in a boosted internal combustion relative to commercially available lubricating oils.

A method for improving wear control, while maintaining or improving fuel efficiency, 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 (i) at least one transition metal salt of a carboxylic acid (e.g., zinc stearate) or (ii) a mixture of at least one transition metal salt of a carboxylic acid (e.g., zinc stearate) and at least one detergent (i.e., an alkali metal or alkaline earth metal salt of an organic acid, or an alkali metal or alkaline earth metal salt of an inorganic acid, or an alkali metal or alkaline earth metal salt of a phenol, or mixtures thereof (e.g., calcium salicylate and/or magnesium sulfonate)), as a minor component. The lubricating oils are useful in internal combustion engines.

A method for improving wear control, while maintaining or improving fuel efficiency, 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 (i) at least one transition metal salt of a carboxylic acid (e.g., zinc stearate) or (ii) a mixture of at least one transition metal salt of a carboxylic acid (e.g., zinc stearate) and at least one detergent (i.e., an alkali metal or alkaline earth metal salt of an organic acid, or an alkali metal or alkaline earth metal salt of an inorganic acid, or an alkali metal or alkaline earth metal salt of a phenol, or mixtures thereof (e.g., calcium salicylate and/or magnesium sulfonate)), as a minor component. The lubricating oils are useful in internal combustion engines.

Disclosed is a MoDTC-free lubricating oil composition for motorcycles which comprises an engine and a clutch, wherein the composition comprises: an oil of lubricating viscosity, a molybdenum compound, and a salicylate detergent having a TBN 100-450 on active basis, wherein the composition lubricates the engine but not the clutch.

Also disclosed is a method for lubricating the engine of a motorcycle, which comprises an engine and a clutch, with a MoDTC-free lubricating oil composition, wherein the composition comprises: an oil of lubricating viscosity, a molybdenum compound, and a salicylate detergent having a TBN 100-450 on active basis, and wherein the composition lubricates the engine but not the clutch.

Disclosed is a MoDTC-free lubricating oil composition for motorcycles which comprises an engine and a clutch, wherein the composition comprises: an oil of lubricating viscosity, a molybdenum compound, and a salicylate detergent having a TBN 100-450 on active basis, wherein the composition lubricates the engine but not the clutch.

Also disclosed is a method for lubricating the engine of a motorcycle, which comprises an engine and a clutch, with a MoDTC-free lubricating oil composition, wherein the composition comprises: an oil of lubricating viscosity, a molybdenum compound, and a salicylate detergent having a TBN 100-450 on active basis, and wherein the composition lubricates the engine but not the clutch.