Patent ID: 7863227

Claim:
A method for enhancing oxidation resistance and thermal breakdown deposit protection of a lubricating oil composition while not adversely affecting seal integrity by combining into the lubricating oil composition comprising a base stock or base oil of lubricating viscosity a combination of an aromatic amine having a molecular weight of at least about 650 in an amount in the range of about 0.1 to 5 wt % based on active ingredient and a low boron content dispersant, the amount of boron in the dispersant being less than about 1.1 wt % but at least 0.05 wt %, the amount of dispersant used being sufficient to provide a boron content of 15 to 100 ppm boron wherein the enhancement of oxidation resistance and thermal breakdown deposit protection while not adversely affecting seal integrity is as compared to lubricating oils which do not contain aromatic amine having a molecular weight of at least 650 and a boron containing dispersant having a boron content of less than 1.1 wt % but at least 0.05 wt % in an amount sufficient to provide a boron content to the lubricating oil of 15 to 100 ppm boron.