Lubricating oil composition

A lubricating oil composition, comprising:

• a base oil (A);
• a neutral phosphorus compound (B), which is a trisubstituted aromatic phosphate, trisubstituted aliphatic phosphate, or mixture of two or more of any of these;
• an acidic phosphorus compound (C);
• a sulfur compound (D);
• and
• a metal salt (E), which is a calcium sulfonate,
• wherein the neutral phosphorus compound (B), in terms of phosphorus atoms, is present in a range of from 100 to 1500 ppm by mass, based on the total lubricating oil composition mass,
• wherein the acidic phosphorus compound (C), in terms of phosphorus atoms, is present in a range of from 10 to 180 ppm by mass, based on total lubricating oil composition mass,
• wherein the acidic phosphorus compound (C) comprises a compound (C1) of formula (c-1), a compound (C2) of formula (c-2), and/or an amine salt (C3) of the compound (C1) or (C2):
• R1 and R2 in formulas (c-1) and (c-2) independently being a hydrocarbon group comprising 6 to 30 carbon atoms, and m and n independently being 1 or 2, wherein the sulfur compound (D), in terms of sulfur atoms, is present in a range of from 200 to 1000 ppm by mass, based on the total lubricating oil composition mass, wherein the sulfur compound (D) comprises a compound (D1) of fonnula (d-1):
• Ra and Rb independently being a hydrocarbon group, and X1 and X2 independently being an integer in a range of from 1 to 3, and
• wherein the metal salt (E), in terms of calcium atoms, is present in a range of from 30 to 180 ppm by mass, based on the total lubricating oil composition mass.