abstract |
This invention relates to a lubricating composition comprising a major amount of an oil of lubricating viscosity, (A) an hydrocarbyl phosphite, wherein each hydrocarbyl group is saturated and independently contains from about 12 to about 24 carbon atoms, (B) an organic polysulfide, and (C) (i) a borated overbased metal salt of an acidic organic compound, (ii) a combination of a borated dispersant and a phosphorus antiwear or extreme pressure agent selected from the group consisting of a phosphoric acid ester or salt thereof, a lower alkyl phosphite, and a phosphorus-containing carboxylic acid, ester, ether, or amide, or (iii) a mixture of (i) and (ii). These compositions provide improved frictional properties to lubricating composition while maintaining the extreme pressure protection of the lubricant. The lubricating compositions have good thermal stability. |