Abstract: A lubricant additive for gear oils and an improved gear oil are disclosed. The additive comprises about 0.01 to about 65 percent, by weight, of solid lubricant particles selected from the group consisting of molybdenum disulfide, graphite, cerium fluoride, zinc oxide, tungsten disulfide, mica, boron nitrate, boron nitride, borax, silver sulfate, cadmium iodide, lead iodide, barium fluoride, tin sulfide, fluorinated carbon, PTFE, intercalated graphite, zinc phosphide, zinc phosphate, and mixtures thereof; combined with about 0.1 to about 25 percent, by weight, of a stabilizing agent consisting of an ethylene-propylene copolymer; and a fluid carrier. The lubricant additive provides the gear oil with improved demulsibility, stability, and compatibility characteristics of the gear oil when contaminated with water.