| abstract |
A composition of an oil of lubricating viscosity, an antioxidant, an anti-nitration agent, and optionally a borated product of an epoxide or the reactive equivalent of an epoxide, provides a desirable lubricant for diesel or natural gas-fueled engines. The composition is substantially free from metals and preferably substantially free from phosphorus. The amount of the antioxidant the antinitration agent are sufficient to reduce the amount of varnish formation in a natural gas engine. |