METHOD FOR IMPROVING FUEL ECONOMY OF A HEAVY DUTY DIESEL ENGINE

摘要

Disclosed is a method for improving the fuel economy of a heavy duty diesel engine which produces a heavily sooted lubricating oil composition during the engine's normal operation. The method involves introducing lubricating the heavy duty diesel engine with a heavy duty diesel engine lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity; and (b) a minor effective amount of an ashless friction modifier comprising a reaction product of a C4 to about C75 fatty acid ester and a mono- or dialkanolamine.