Lubricating oil compositions with engine wear protection

A method for improving wear control, while maintaining or improving solubility and fuel efficiency, in an engine or other mechanical component lubricated with a low phosphorus lubricating oil by using as the low phosphorus lubricating oil a low phosphorus formulated oil, said low phosphorus formulated oil having a composition comprising:

• a lubricating oil base stock as a major component;
• at least one phosphorus-containing additive;
• and
• at least one metal salt of a carboxylic acid, as a minor component, that contains no sulfur or phosphorus, wherein the metal is selected from the group consisting of palladium (Pd), silver (Ag), gold (Au), zinc (Zn), and mixtures thereof;
• and the carboxylic acid is selected from the group consisting of an aliphatic carboxylic acid, a cycloaliphatic carboxylic acid, an aromatic carboxylic acid, and mixtures thereof;
• wherein a molar ratio of (zinc+palladium+silver+gold)/phosphorus of said formulated oil is greater than 1.0;
• and wear control is improved and solubility and fuel efficiency are maintained or improved as compared to wear control, solubility and fuel efficiency achieved using a lubricating oil containing a minor component other than the at least one metal salt of a carboxylic acid.