The use as a valve deposit controlling additive in a fuel composition for a direct injection spark-ignition internal combustion engine of a combination of: a) at least one hydrocarbyl-substituted aromatic compound; and b) at least one polyalkylene amine.

The use as a valve deposit controlling additive in a fuel composition for a direct injection spark-ignition internal combustion engine of a combination of: a) at least one hydrocarbyl-substituted aromatic compound; and b) at least one polyalkylene amine.

The use of tetrahydrobenzoxazines I ##STR00001##
where R.sup.1 is a hydrocarbyl radical and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently hydrogen atoms, hydroxyl groups or hydrocarbyl radicals, and where R.sup.2 to R.sup.5 may also form a second and a third tetrahydrooxazine ring, with the proviso that at least one of the substituents has from 4 to 3000 carbon atoms and the remaining substituents, when they are hydrocarbyl radicals, each have from 1 to 20 carbon atoms, as stabilizers for stabilizing inanimate organic material, especially turbine fuels, against the action of light, oxygen and heat.

The use of tetrahydrobenzoxazines I ##STR00001##
where R.sup.1 is a hydrocarbyl radical and R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently hydrogen atoms, hydroxyl groups or hydrocarbyl radicals, and where R.sup.2 to R.sup.5 may also form a second and a third tetrahydrooxazine ring, with the proviso that at least one of the substituents has from 4 to 3000 carbon atoms and the remaining substituents, when they are hydrocarbyl radicals, each have from 1 to 20 carbon atoms, as stabilizers for stabilizing inanimate organic material, especially turbine fuels, against the action of light, oxygen and heat.

A composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams includes a H2S scavenger selected from oxazolidine compounds, triazine and metal-based carboxylate compounds, and a synergistic additive allowing boosting the effect of the H2S scavenger compound.

The present technology is related to imide containing quaternary ammonium salts having a hydrocarbyl substituent of number average molecular weight less 300, and additive packages having such quaternary ammonium salts and improved stability.

New, highly effective substantially pure Mannich detergents for use in hydrocarbon fuels reduce engine deposits in spark and compression ignition internal combustion engines. The Mannich condensation reaction products are obtainable by reacting: (i) a polyamine having primary amino groups, (ii) a hydrocarbyl-substituted hydroxyaromatic compound, and (iii) an aldehyde, wherein the reaction is conducted at in a molar ratio of (i):(ii):(iii) of approximately 1:2:3. The Mannich detergent compounds may be dispersed in a liquid carrier to provide a fuel additive concentrate for hydrocarbon engine fuels which effectively control engine deposit formation in intake valves, port fuel injectors and combustion chambers.

New, highly effective substantially pure Mannich detergents for use in hydrocarbon fuels reduce engine deposits in spark and compression ignition internal combustion engines. The Mannich condensation reaction products are obtainable by reacting: (i) a polyamine having primary amino groups, (ii) a hydrocarbyl-substituted hydroxyaromatic compound, and (iii) an aldehyde, wherein the reaction is conducted at in a molar ratio of (i):(ii):(iii) of approximately 1:2:3. The Mannich detergent compounds may be dispersed in a liquid carrier to provide a fuel additive concentrate for hydrocarbon engine fuels which effectively control engine deposit formation in intake valves, port fuel injectors and combustion chambers.

A fuel composition comprising a base fuel and at least one viscosity index (VI) improving additive, wherein the viscosity index (VI) improving additive is a functionalized dispersant olefin copolymer. The viscosity index (VI) improving additive provides improved power output and/or acceleration characteristics.

A fuel composition comprising a base fuel and at least one viscosity index (VI) improving additive, wherein the viscosity index (VI) improving additive is a functionalized dispersant olefin copolymer. The viscosity index (VI) improving additive provides improved power output and/or acceleration characteristics.