Fuel compositions comprising at least 10 ppm by weight of a succinic ester acid amine salt or a succinamide acid amine salt (both “amine salt(s)”). The amine salt is the product of (a) and (b), wherein: (a) is an amine with (i) at least one tertiary nitrogen and (ii) at least one hydroxy alkyl functional group and/or at least one secondary amine functionality; and (b) is a hydrocarbyl-substituted succinic acid/or anhydride. The molar ratio of (a) to (b) may range from 3:1 to 1:3. The fuel composition may comprise gasoline, oxygenate, or mixtures thereof. Methods and uses for reducing carbonaceous deposits in an engine comprising operating the engine using the fuel composition having an amine salt therein.

The present invention relates to a composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, the composition comprising an oxazolidine compound and a synergistic additive.

A fuel composition for use in internal-combustion engines has a fuel component, an alcohol component, a water component, a microemulsion blend, and a cetane-enhancer component. The microemulsion blend includes at least one of lower grade fatty acid derivatives being present in an amount effective for the fuel, alcohol, and water components to form a microemulsion blend. The emulsifier is present in an amount effective for the biodiesel fuel, alcohol, water, and emulsifier to form an emulsion.

The present invention provides a fuel oil composition, including: a fuel oil base oil having a sulfur element content of from 0.01 mass % to 0.50 mass %; and a calcium salicylate having a total base number of from 100 mgKOH/g to 1,200 mgKOH/g.

A diesel fuel composition comprising as an additive an ester compound which is the reaction product of an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol of formula H—(OR).sub.n—OH, wherein R is an optionally substituted alkylene group and n is at least 1.

A gasoline fuel composition comprising as an additive an ester compound which is the reaction product of an optionally substituted polycarboxylic acid or an anhydride thereof and an alcohol or formula H—(OR).sub.n—OR.sup.1, wherein R is an optionally substituted alkylene group; R.sup.1 is hydrogen or an optionally substituted hydrocarbyl group, and n is 0 or a positive integer; wherein n is not O when R.sup.1 is hydrogen.

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 diesel fuel composition comprising as an additive an ester compound which is the reaction product of an optionally substituted polycarboxylic acid or an anhydride thereof and a polyhydric alcohol of formula H—(OR).sub.n—OH, wherein R is an optionally substituted alkylene group and n is at least 1.

The present invention relates to a low-temperature additive for fuel oils having a sulfur content of less than 50 ppm, comprising i) at least one oil-soluble amide-ammonium salt of a polycarboxylic acid with a mono- and/or dialkylamine (A) and ii) 5-100% by weight, based on the amount of amide-ammonium salt (A), of an oil-soluble amine (B), and iii) 0.1 to 10 parts by weight, based on the amount of amide-ammonium salt (A), of a resin formed from at least one aromatic compound bearing an alkyl radical and an aldehyde and/or ketone (D).

A fuel composition comprising a fuel and a lubricity additive where the lubricity additive is selected from (1) 1-Lauroyl-rac-glycerol, (2) Dodecanamide, N-hydroxy-, or (3) 2-Ethylhexanoic acid and the fuel is gasoline.