Lubricant compositions containing controlled release additives

A method for controlled release of one or more lubricating oil additives into a lubricating oil, said method comprising:

• using as the lubricating oil a formulated oil, said formulated oil having a composition comprising a lubricating oil base stock as a major component;
• and a mixture of (i) one or more chemically protected lubricating oil additives comprising a chemically protected phenolic antioxidant, and (ii) one or more unprotected lubricating oil additives comprising an unprotected aminic antioxidant, as a minor component;
• wherein the one or more chemically protected lubricating oil additives are inactive with respect to their antioxidant function;
• and
• converting the one or more chemically protected lubricating oil additives into one or more unprotected lubricating oil additives comprising an active —OH or a —NH group in the lubricating oil in-service in an engine or other mechanical component.

A method for improving oxidative stability of a lubricating oil and extending performance life of one or more lubricating oil additives, said method comprising:

• using as the lubricating oil a formulated oil, said formulated oil having a composition comprising a lubricating oil base stock as a major component;
• and a mixture of (i) one or more chemically protected lubricating oil additives comprising a chemically protected phenolic antioxidant, and (ii) one or more unprotected lubricating oil additives comprising an unprotected aminic antioxidant, as a minor component;
• wherein the one or more chemically protected lubricating oil additives are inactive with respect to their antioxidant function;
• and
• converting the one or more chemically protected lubricating oil additives into one or more unprotected lubricating oil additives comprising an active —OH or a —NH group in the lubricating oil in-service in an engine or other mechanical component.