This invention relates to a lubricating oil composition comprising or resulting from the admixing of: (i) base oil, (ii) an overbased calcium based detergent at treat level to deliver between 500 to 1300 ppm by weight of calcium to the composition; (iii) an overbased magnesium based detergent at treat level to deliver between 500 to 1300 ppm by weight of magnesium to the composition; wherein the total weight of combined calcium and magnesium in the composition ranges from 1000 ppm to 1800 ppm. The composition has a total sulfated ash of less than or equal to 1.0 wt. %, a high temperature high shear viscosity at 150 C. of greater than or equal to 1.8 mPa.Math.s and less than or equal to 2.9 mPa.Math.s, and a total phosphorous level of less than or equal to 0.080 wt. %. The inventive composition provides a 5% to 60% decrease in journal bearing wear as measured by maximum average wear in microns using the TE-92 start/stop test method compared to a lubricating oil composition of comparable HTHS, but not including the mixture of the overbased calcium based detergent and the overbased magnesium based detergent. Also provided are a method of decreasing journal bearing wear in an internal combustion engine and a method of making the lubricating oil composition.

A lubricant additive concentrate having a kinematic viscosity of from about 40 to about 300 cSt at 100 C., containing a dispersant-detergent colloid complex, including a polybutenyl succinimide dispersant that is the reaction product of a polyamine and polybutenyl succinic anhydride (PIBSA) derived from polybutene having a number average molecular weight (M.sub.n) of from about 1300 to about 2500 and a terminal vinylidene content of at least about 65%, and succinic and/or maleic anhydride via an ene maleation process, the PIBSA having a succinic anhydride (SA) functionality (F) of greater than 1.7 and less than about 2.5; and a detergent colloid including overbased detergent having a total base number (TBN) of from about 370 to about 1000 mg KOH/g derived from one or more surfactants selected from (i) sulfonate; (ii) phenate; and (iii) carboxylate surfactant; in which the mass ratio of the dispersant to the overbased detergent colloid in the concentrate is from about 0.5 to about 5.0; and the dispersant and overbased colloidal together constitute at least 28 mass %, of the concentrate.

A composition of an oil-soluble ionic detergent that does not contribute metal ions to the composition, and which comprises a quaternary non-metallic pnictogen cation and an organic anion having at least one hydrocarbyl group of sufficient length to impart oil solubility to the detergent, the detergent having a total base number (TBN) to total acid number (TAN) ratio of at least 2:1 imparts ash-free basicity to a lubricant composition.

A composition of an oil-soluble ionic detergent that does not contribute metal ions to the composition, and which comprises a quaternary non-metallic pnictogen cation and an organic anion having at least one hydrocarbyl group of sufficient length to impart oil solubility to the detergent, the detergent having a total base number (TBN) to total acid number (TAN) ratio of at least 2:1 imparts ash-free basicity to a lubricant composition.

The invention provides a lubricating composition containing a -amino compound. The invention further relates to a method of lubricating an internal combustion engine by lubricating the engine with the lubricating composition. The invention further relates to the use of the -amino carbonyl compound as copper corrosion inhibitors, friction control agents, antiwear and/or extreme pressure agents.