A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−. ##STR00001##

A fuel stabilizer formulation includes a hybrid component that acts as an antioxidant, a chelating agent, and lubricant when added to the fuel, one or more vapor suppressants, and a water scavenger. Furthermore, the formulation may include components that bond with gasoline compounds to prevent evaporation of low-end components, form a layer along with the engine metal that prevents condensed water from corroding the metal, prevent corroded metal ions from destabilizing gasoline compounds into resin, and scavenge water to prevent water deposits at the bottom of the tank which limits biological activity, resulting in an overall improvement in oxidation stability over conventional fuel stabilizers.

A fuel stabilizer formulation includes a hybrid component that acts as an antioxidant, a chelating agent, and lubricant when added to the fuel, one or more vapor suppressants, and a water scavenger. Furthermore, the formulation may include components that bond with gasoline compounds to prevent evaporation of low-end components, form a layer along with the engine metal that prevents condensed water from corroding the metal, prevent corroded metal ions from destabilizing gasoline compounds into resin, and scavenge water to prevent water deposits at the bottom of the tank which limits biological activity, resulting in an overall improvement in oxidation stability over conventional fuel stabilizers.

Lubricity additives for hydrocarbon fuels are provided according to formula I:

##STR00001##

wherein n is 1 or 0; each Q is independently selected from oxygen and sulfur; each R is independently selected from C8-C60 alkenyl groups which are substituted or unsubstituted; and L is a linking group comprising 0-20 carbons which may be substituted or unsubstituted and may optionally comprise catenary heteroatoms. Fuel mixtures comprising a hydrocarbon fuel; and a lubricity additive according to the present disclosure are also provided. Methods of making lubricity additives comprise reacting an alkenyl succinic anhydrides (ASA's) with certain bisamides or bisthioamides.

Lubricity additives for hydrocarbon fuels are provided according to formula I:

##STR00001##

wherein n is 1 or 0; each Q is independently selected from oxygen and sulfur; each R is independently selected from C8-C60 alkenyl groups which are substituted or unsubstituted; and L is a linking group comprising 0-20 carbons which may be substituted or unsubstituted and may optionally comprise catenary heteroatoms. Fuel mixtures comprising a hydrocarbon fuel; and a lubricity additive according to the present disclosure are also provided. Methods of making lubricity additives comprise reacting an alkenyl succinic anhydrides (ASA's) with certain bisamides or bisthioamides.

The present invention relates to the use, for reducing deposits in the internal parts of a spark ignition engine, of a fuel composition comprising at least three additives: a quaternary ammonium salt, a non-quaternary polyisobutylene succinimide and a Mannich base which is different from the other additives. The composition is such that the mass ratio of the quantity of the first additive to the quantity of the second additive is in the range from 0.2:1 to 2.5:1.

The present invention discloses additive package comprising a mixture of (a) 6-10% by weight of fatty acid (b) 7-15% by weight of alkoxy ether and (c) 60-85% by weight of linear or branched chain monohydroxylated aliphatic saturated alcohol (C2-C8) for improving stability of mixtures of methanol-gasoline, ethanol-gasoline blends containing at least 5-15% by volume of short chain alkanol (methanol/ethanol). The additive composition is added to the alcohol-gasoline blends to improve low temperature stability, provides corrosion protection and to normalize vapor pressure of methanol/ethanol-gasoline blends.

The present invention discloses additive package comprising a mixture of (a) 6-10% by weight of fatty acid (b) 7-15% by weight of alkoxy ether and (c) 60-85% by weight of linear or branched chain monohydroxylated aliphatic saturated alcohol (C2-C8) for improving stability of mixtures of methanol-gasoline, ethanol-gasoline blends containing at least 5-15% by volume of short chain alkanol (methanol/ethanol). The additive composition is added to the alcohol-gasoline blends to improve low temperature stability, provides corrosion protection and to normalize vapor pressure of methanol/ethanol-gasoline blends.

A fuel composition comprising as an additive the reaction product of a polycarboxylic acid compound of formula (I): (I) or an anhydride thereof; and an alcohol having at least 5 carbon atoms; wherein each of n and m may be 0 or a positive integer.

##STR00001##

A fuel composition comprising as an additive the reaction product of a polycarboxylic acid compound of formula (I): (I) or an anhydride thereof; and an alcohol having at least 5 carbon atoms; wherein each of n and m may be 0 or a positive integer.

##STR00001##