Abstract: A diesel fuel containing a soot dispersant additive which is a grafted and derivatized low molecular weight copolymer of ethylene and at least one C3-C10 alpha monoolefin is provided. Also provided is a method for improving the fuel economy of a diesel engine which comprises operating the diesel engine with a fuel composition comprising (a) a major amount of a diesel fuel and (b) a minor fuel economy improving effective amount of the soot dispersant additive.

Abstract: A diesel fuel containing a soot dispersant additive which is a grafted and derivatized low molecular weight copolymer of ethylene and at least one C3-C10 alpha monoolefin is provided. Also provided is a method for improving the fuel economy of a diesel engine which comprises operating the diesel engine with a fuel composition comprising (a) a major amount of a diesel fuel and (b) a minor fuel economy improving effective amount of the soot dispersant additive.

Abstract: A lubricating oil composition is provided which comprises (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and (b) a friction modifying effective amount of an ashless friction modifier comprising a reaction product of a C4 to about C75 fatty acid ester and an alkanolamine. Particularly preferred is a lubricating oil composition comprising (a) an oil of lubricating viscosity having a kinematic viscosity of about 2 to 10.5 cSt at 100° C. and comprising about 55 to about 85 weight percent of a first lubricating oil, and about 15 to about 45 weight percent of a second lubricating oil wherein the kinematic viscosity of the second lubricating oil is lower than the kinematic viscosity of the first lubricating oil at 100° C.; and (b) about 0.5 to about 5.0 weight percent, based on the total weight of the lubricating oil composition, of an ashless friction modifier comprising a reaction product of a C4 to about C75 fatty acid ester and an alkanolamine.