A method minimizes power loss in a direct injection diesel engine by adding a copolymer to a diesel fuel composition. The copolymer contains, in a copolymerized form, (A) maleic anhydride, (B) an α-olefin having from 12 to 30 carbon atoms, (C) optionally an additional aliphatic or cycloaliphatic olefin which has at least 4 carbon atoms and is different from monomer (B), and (D) optionally an additional copolymerizable monomer other than monomers (A), (B) and (C). Monomer (D) can be a vinyl ester, a vinyl ether, a (meth)acrylic ester of an alcohol having at least 5 carbon atoms, an allyl alcohol or an ester thereof, a N-vinyl compound, an ethylenically unsaturated aromatic, an α,β-ethylenically unsaturated nitrile, a (meth)acrylamide, or an allylamine. Anhydride functionalities present in the copolymer are partly reacted with at least one compound (E) comprising an alcohol group and/or an amino group, and the anhydride functionalities present are hydrolyzed.

A method minimizes power loss in a direct injection diesel engine by adding a copolymer to a diesel fuel composition. The copolymer contains, in a copolymerized form, (A) maleic anhydride, (B) an α-olefin having from 12 to 30 carbon atoms, (C) optionally an additional aliphatic or cycloaliphatic olefin which has at least 4 carbon atoms and is different from monomer (B), and (D) optionally an additional copolymerizable monomer other than monomers (A), (B) and (C). Monomer (D) can be a vinyl ester, a vinyl ether, a (meth)acrylic ester of an alcohol having at least 5 carbon atoms, an allyl alcohol or an ester thereof, a N-vinyl compound, an ethylenically unsaturated aromatic, an α,β-ethylenically unsaturated nitrile, a (meth)acrylamide, or an allylamine. Anhydride functionalities present in the copolymer are partly reacted with at least one compound (E) comprising an alcohol group and/or an amino group, and the anhydride functionalities present are hydrolyzed.

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.

An anti-static fuel additive composition and method for using the composition to reduce or prevent buildup of electrostatic charge is described. The anti-static fuel additive composition comprises a polysulfone and a copolymer derived from reaction of an alkanolamine and a hydrocarbyl-substituted 4-membered to 7-memebered ring anhydride; for example, a hydrocarbyl-substituted succinic anhydride, a hydrocarbyl-substituted maleic anhydride, a hydrocarbyl-substituted phthalic anhydride, or a combination thereof.

An anti-static fuel additive composition and method for using the composition to reduce or prevent buildup of electrostatic charge is described. The anti-static fuel additive composition comprises a polysulfone and a copolymer derived from reaction of an alkanolamine and a hydrocarbyl-substituted 4-membered to 7-memebered ring anhydride; for example, a hydrocarbyl-substituted succinic anhydride, a hydrocarbyl-substituted maleic anhydride, a hydrocarbyl-substituted phthalic anhydride, or a combination thereof.

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.

Methods of reducing stochastic pre-ignition events and/or carbonaceous deposits in a gasoline-fueled engine by adding at least 10 ppm by weight of a compound having at least one alkyl succinic acid group to a gasoline fuel, wherein said compound is the product of (a) and (b), wherein:

(a) is an amine with at least one tertiary nitrogen, water, or a hydrocarbyl substituted alcohol; and

(b) is a hydrocarbyl-substituted succinic acid and/or anhydride.

A fuel composition comprising as an additive the reaction product of a polycarboxylic acid having no more than 5 carbon atoms per carboxylic acid group, or an anhydride thereof and an alcohol having at least 5 carbon atoms.

Method for reducing intake valve deposits in a spark ignition internal combustion engine which is fuelled with a gasoline fuel composition, wherein the method comprises introducing into the engine an aqueous based composition, wherein the aqueous based composition comprises (i) water, (ii) from 0 vol % to 40 vol % freezing point suppression agent, (iii) from 0 vol % to 10 vol % of surfactant, and (iv) an amine compound in a blending amount of from 0 ppmw to 1000 ppmw.

A composition comprising at least one fuel that is a diesel fuel, a biodiesel fuel, or combinations thereof and less than 100 ppm, less than 50 ppm (or less than 25 ppm, less than 10 ppm, 1 to 7 ppm, or 5 to 7 ppm) of an alkylene-coupled C.sub.10 to C.sub.60 (or C.sub.10 to C.sub.40, C.sub.14 to C.sub.32 or C.sub.24 to C.sub.28) alkylphenol; 25 to 500 ppm (or 50 to 500 ppm, or 150 to 450 ppm or 250 to 450 ppm, or 250 to 400 ppm) of a terpolymer; and 5 to 90 ppm, (or 10 to 70 ppm, to 60 ppm, or 10 to 55 ppm) of hydrocarbyl-substituted amine detergent having at least one tertiary amino group.

Methods of reducing the cold filter plugging point (“CFPP”) of a fuel, said method comprising adding the following components: less than 100 ppm, less than 50 ppm (or less than 25 ppm; less than 10 ppm, 1 to 7 ppm, or 5 to 7 ppm) of an alkylene-coupled C.sub.10 to C.sub.60 (or C.sub.10 to C.sub.40, C.sub.14 to C.sub.32 or C.sub.24 to C.sub.28) alkylphenol; 25 to 500 ppm (or 50 to 500 ppm, or 150 to 450 ppm or 250 to 450 ppm, or 250 to 400 ppm) of a terpolymer; and 5 to 90 ppm, (or 10 to 70 ppm, to 60 ppm, or 10 to 55 ppm) of hydrocarbyl-substituted amine detergent having at least one tertiary amino group.

Uses of a fuel additive composition to reduce the cold filter plugging point (“CFPP”) of a fuel, wherein the fuel additive composition comprises: 0.2 to 3 wt % of an alkylene-coupled C.sub.10 to C.sub.60 (or C.sub.10 to C.sub.40, C.sub.14 to C.sub.32 or C.sub.24 to C.sub.28) alkylphenol; 10 to 50 wt % of a terpolymer; and 2 to 10 wt % of hydrocarbyl-substituted amine detergent having at least one tertiary amino group; and an optional solvent.