Abstract: Intake valve deposits in port fuel injected engines are reduced by using a fuel containing a mixture of (a) an oil soluble polyamine selected from (i) an aliphatic alkylene polyamine containing at least one olefinic polymer chain attached to a nitrogen and/or carbon atom of the alkylene radical(s) connecting the amino nitrogen atoms and said polyamine having a number average molecular weight in the range of from about 600 to about 10,000, (ii) a Mannich polyamine comprising the condensation product of a high molecular weight sulfur-free alkyl-substituted hydroxyaromatic compound wherein the alkyl group has a number average molecular weight from about 600 to about 10,000, an amine which contains an amino group having at least one active hydrogen atom, and an aldehyde, wherein the respective molar ratio of reactants is 1:0.1-10:0.

Abstract: The present invention is a process for reducing the smoke emissions from a jet fuel engine by combusting a jet fuel range hydrocarbon in a jet engine wherein prior to combusting the jet fuel in the engine the jet fuel is treated by the following process: (a) contacting the jet fuel with at least one adsorbent in at least one adsorbent bed under suitable process conditions such that the smoke point of the jet fuel is increased and (b) recovering the jet fuel.

Abstract: This invention is a method for reducing the particulate emissions tendency of diesel fuel. Also the piston ring sticking, and deposit formation tendency of diesel fuel on the injector and combustion chamber of an internal combustion diesel fuel are reduced. The diesel fuel under the method of this invention is fed to at least one adsorbent bed in which the diesel fuel is contacted with one or more adsorbents under suitable process conditions such that there is a reduction in content of impurities in the fuel which cause the particulate emission causing tendency, piston ring sticking, and deposit formation tendency of the diesel fuel on the injector and/or combustion chamber.

Abstract: Improved gasoline compositions containing a minor amount of a polyalphaolefin having a viscosity at 100.degree. C. from 2 to 20 centistokes, and optionally also an aliphatic polyamine, an alkali or alkaline earth metal salt of a succinic acid derivative, and/or a polyolefin; together with a concentrate for the production of such gasoline composition and a method of operating a spark-ignition engine using such gasoline composition.

Abstract: A sleeve is provided to be retrofitted to a diesel fuel tank filling nozzle that has selective leaching properties such that an antifoamant agent, such as a silicon compound, migrates in a selective manner to the surface of the sleeve intermittent to passage of the diesel fuel over the sleeve. An initial gust of the diesel fuel will carry the antifoamant material from the nozzle sleeve into the consumer's fuel tank where it exhibits antifoaming activities and thereby permits a top-up of the diesel fuel tank of the vehicle.

Abstract: Diesel fuel composition comprising a hydrocarbonaceous diesel fuel having a cetane number in the range from 25 to 60, a polyolefin and a polyamine wherein at least one hydrocarbon chain has at least 25 carbon atoms and is bound directly to a nitrogen atom.

Abstract: A method is disclosed for reducing combustion chamber deposits in an internal combustion engine by the passage of an aqueous deadhering agent such as water to the combustion chamber at cold start conditions and permitting the engine to crank for a period of time until said deposits deadhere from the walls of the combustion chamber. The aqueous deadhering agent can be water or the same with a diluent, such as a lower alkyl ketone. This invention is applicable to combustion chamber deposits which have resulted from the use of an additive agent, such as an amine-urea type detergent additive in as low a concentration in gasoline fuel as 50 ppm.

Abstract: A gasoline motor fuel composition is disclosed comprising a minor and effective amount of at least one sulfurized dioleyl ester of norbornene. Also disclosed is a method for reducing fuel consumption of internal combustion engines by incorporating a sulfurized dioleyl ester of norbornene into the gasoline fuel to said engines and operating the engines for a time sufficient to disperse said ester throughout the oil-contacted surfaces of the engine.

Abstract: The control or reversal of octane requirement increase phenomenon together with improved fuel economy in a spark ignition internal combustion engine is achieved by introducing with the combustion charge a fuel composition containing an octane requirement increase-inhibiting amount of (a) certain oil soluble aliphatic polyamines and (b) certain low molecular weight polymers and/or copolymers of monoolefins having up to 6 carbon atoms, in certain ratio.

Abstract: Reduced fuel consumption of spark ignition reciprocating internal combustion engines is achieved by coating the intake port area of the engine with a thermally insulating material.

Abstract: The inhibition or prevention of octane requirement increase in a spark ignited internal combustion engine is achieved by introducing with the combustion charge a fuel composition containing an octane requirement increase-inhibiting amount of: (a) certain cyclomatic manganese compounds, (b) certain oil soluble aliphatic polyamines, and (c) oil of lubricating viscosity in certain range of weight ratio of (a):(b):(c).