Lubricating oil composition

A lubricating oil composition made by combining:

• (A) a base oil;
• (B) a boron-containing compound represented by the formulae
• wherein in Formulae (B-I), (B-II) and (B-III), each R is independently an organic group and any two adjacent R groups may together form a cyclic group;
• and
• (E) an alkali or an alkaline earth metal salt of a hydrocarbon-substituted saligenin represented by the formula
• wherein in Formula (E-I):
• each X independently is —CHO or —CH2OH;
• each Y independently is —CH2— or —CH2OCH2—;
• wherein the —CHO groups comprise at least about 10 mole percent of the X and Y groups;
• each M is independently the valance of an alkali or alkaline earth metal ion;
• each R is independently a hydrocarbyl group containing 1 to about 60 carbon atoms;
• m is 0 to about 10;
• n is 0 or 1 provided that when n is 0 the M is replaced with H;
• and each p is independently 0, 1, 2, or 3;
• provided that at least one aromatic ring contains an R substituent and that the total number of carbon atoms in all R groups is at least 7;
• and further provided that if m is 1 or greater, then one of the X groups can be —H;
• the lubricating oil composition containing sulfur, boron and optionally phosphorus with the ratio of sulfur to boron to phosphorus being represented by the formula
• S1+5B1+3P1>0.35
• wherein S1 is the concentration in percent by weight of sulfur in the composition, B1 is the concentration in percent by weight of boron in the composition, and P1 is the concentration in percent by weight of phosphorus in the composition;
• the concentration of sulfur in the lubricating oil composition being from about 0.01% to about 0.25% by weight;
• the concentration of phosphorus in the lubricating oil composition being up to about 0.08% by weight.

A lubricating oil composition made by combining:

• (A) a base oil;
• (B) a boron-containing compound represented by either:
• the formulae
• wherein in Formulae (B-I), (B-II) and (B-III), each R is independently a hydrocarbon group of 1 to about 10 carbon atoms and any two adjacent R groups may together form a cyclic group;
• or by the formula
• wherein in Formula (B-I-1):
• R1, R2, R3 and R4 are independently hydrocarbyl groups of 1 to about 12 carbon atoms;
• and R5 and R6 are independently alkylene groups of about 2 or about 3 carbon atoms;
• (C) a polyisobutene substituted succinimide containing at least about 50 aliphatic carbon atoms in the polyisobutene group;
• (D) a calcium or magnesium salt of an organic sulfur acid, a carboxylic acid, a lactone or a phenol;
• (E) a compound represented by the formula
• wherein in Formula (E-I):
• each X independently is —CHO or —CH2OH;
• each Y independently is —CH2— or —CH2OCH2—;
• wherein the —CHO groups comprise at least about 10 mole percent of the X and Y groups;
• each M is a calcium or magnesium ion;
• each R is independently a hydrocarbyl group containing 1 to about 60 carbon atoms;
• m is 0 to about 10;
• n is 0 or 1 provided that when n is 0 the M is replaced with H;
• and each p is independently 0, 1, 2, or 3;
• provided that at least one aromatic ring contains an R substituent and that the total number of carbon atoms in all R groups is at least 7;
• and further provided that if m is 1 or greater, then one of the X groups can be —H;
• and
• (F) a zinc dialkyl dithiophosphate;
• the lubricating oil composition containing sulfur, boron and phosphorus with the ratio of sulfur to boron to phosphorus being represented by the formula
• S1+5B1+3P1>0.35
• wherein S1 is the concentration in percent by weight of sulfur in the composition, B1 is the concentration in percent by weight of boron in the composition, and P1 is the concentration in percent by weight of phosphorus in the composition;
• the concentration of sulfur in the lubricating oil composition being from about 0.01% to about 0.25% by weight;
• the concentration of phosphorus in the lubricating composition being up to about 0.08% by weight.