An auxiliary or additive fluid for associated use with the primary diesel or related fuel, for application for reduction of exhaust pollution, and for motor or truck vehicle, or the like, includes the nozzle, the nozzle having its spout extending from its forward end, the spout having an outer sleeve, an inner sleeve through which the fluid flows during dispensing, a lower sleeve capable of shifting within the outer sleeve, and integrated with a safety valve sleeve, and biased axially inwardly of the spout when it is inserted into the fluid intake pipe of a vehicle intake for a fluid tank. A primary safety valve extends through the lower spout sleeve, and the integral safety valve sleeve is maintained in a fixed position, and normally is sealed into closure within the lower end of the lower spout sleeve. But, when the lower spout sleeve is forced axially inwardly, it unseats the safety valve from its sealing therewith, to open the spout for the dispensing of the fuel when the nozzle is actuated to allow fluid flow. In addition, a flow path for air that is normally closed by a check valve, is likewise opened, to allow for the passage of air to maintain the inoperativeness of the automatic shut-off, until such time as the fluid flow closes off the lower end said passage, initiating the automatic shut-off of the fluid dispensing nozzle, when the intake of air is blocked.