Lubricating oil compositions and use thereof for improving journal bearing wear in internal combustion engines

A method of decreasing journal bearing wear in an internal combustion engine comprising:

• providing to the internal combustion engine a lubricating oil composition comprising or resulting from the admixing of:
• an oil of lubricating viscosity at greater than 80 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;
• an overbased calcium salicylate detergent with a Total Base Number (KOH/g) greater than or equal to 150 and less than or equal to 300 and at treat level to deliver between 800 to 1100 ppm by weight of calcium to the composition;
• and
• an overbased magnesium salicylate detergent with a Total Base Number (KOH/g) greater than or equal to 240 and less than or equal to 450 and at treat level to deliver between 600 to 1000 ppm by weight of magnesium to the composition;
• wherein the total weight of combined calcium and magnesium in the composition ranges from 1600 ppm to 1800 ppm;
• wherein the ratio of calcium loading to magnesium loading in the composition is from 40:60 to 60:40 based on weight % in the lubricating oil composition;
• and
• the lubricating oil composition having a total sulfated ash of less than or equal to 1.0 wt. %, a high temperature high shear viscosity at 150° C. (HTHS) as determined according to ASTM D4683-20 of greater than or equal to 1.8 mPa·s and less than or equal to 2.9 mPa·s, and a total phosphorous level of less than or equal to 0.080 wt. %, and
• wherein the lubricating oil 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 a mixture of an overbased calcium salicylate detergent and an overbased magnesium salicylate detergent at a combined calcium and magnesium loading in the composition ranging from 1600 ppm to 1800 ppm, and
• wherein a shell material of the journal bearing is a non-ferrous material selected from the group consisting of a bimetal, a trimaterial/metal and a solid material.

A method of making a lubricating oil composition comprising combining or admixing:

• (i) an oil of lubricating viscosity at greater than 80 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;
• (ii) an overbased calcium salicylate detergent with a Total Base Number (KOH/g) greater than or equal to 150 and less than or equal to 300 and at treat level to deliver between 800 to 1100 ppm by weight of calcium to the composition;
• and
• (iii) an overbased magnesium salicylate detergent with a Total Base Number (KOH/g) greater than or equal to 240 and less than or equal to 450 and at treat level to deliver between 600 to 1000 ppm by weight of magnesium to the composition;
• wherein the total weight of combined calcium and magnesium in the composition ranges from 1600 ppm to 1800 ppm;
• wherein the ratio of calcium loading to magnesium loading in the composition is from 40:60 to 60:40 based on weight % in the lubricating oil composition;
• and
• the lubricating oil composition having a total sulfated ash of less than or equal to 1.0 wt. %, a high temperature high shear viscosity at 150° C. (HTHS) as determined according to ASTM D4683-20 of greater than or equal to 1.8 mPa·s and less than or equal to 2.9 mPa·s, and a total phosphorous level of less than or equal to 0.080 wt. %, and
• wherein the lubricating oil 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 a mixture of an overbased calcium salicylate detergent and an overbased magnesium salicylate detergent at a combined calcium and magnesium loading in the composition ranging from 1600 ppm to 1800 ppm, and
• wherein a shell material of the journal bearing is a non-ferrous material selected from the group consisting of a bimetal, a trimaterial/metal and a solid material.