Abstract: This invention relates to a lubricating composition comprising a major amount of an oil of lubricating viscosity and at least one metal-free thiophosphorus acid ester, at least one amine salt of the thiophosphorus acid ester, or a mixture thereof, wherein the thiophosphorus acid ester contains at least one hydrocarbyl terminated oxyalkylene group, at least one hydrocarbyl terminated polyoxyalkylene group, or a mixture thereof. In one embodiment, the thiophosphorus acid ester is a thiophosphorus acid ester represented by the following formula ##STR1## wherein X.sub.1, X.sub.2, and X.sub.3 are oxygen or sulfur, provided that at least one of X.sub.1, X.sub.2, and X.sub.3 is sulfur; R.sub.1 is a hydrocarbyl group; R.sub.2 is an alkylene group; R.sub.3 is hydrogen or a hydrocarbyl group; x is a number from 1 to about 40; and a is 0, 1, or 2, or at least one salt of the thiophosphorus acid ester.