Abstract: A quaternary ammonium compound of formula (X): wherein R0, R1, R2 and R3 is each individually an optionally substituted alkyl, alkenyl or aryl group and R includes an optionally substituted hydrocarbyl moiety having at least 5 carbon atoms.

Abstract: A method of reducing deposits in a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising a detergent additive which is not a quaternary ammonium salt or a Mannich reaction product; and a quaternary ammonium salt additive comprising the reaction product of nitrogen containing species having at least one tertiary amine group and a quaternizing agent; wherein the nitrogen containing species is selected from: (i) the reaction product of a hydrocarbyl-substituted acylating agent and a compound comprising at least one tertiary amine group and a primary amine, secondary amine or alcohol group; (ii) a Mannich reaction product comprising a tertiary amine group; and (v) a polyalkylene substituted amine having at least one tertiary amine group.

Abstract: A quaternary ammonium compound which is the reaction product of: (a) a tertiary amine having a molecular weight of less than 1000; (b) an acid-activated alkylating agent; and (c) a diacid including an optionally substituted hydrocarbyl moiety having at least (5) carbon atoms.

Abstract: A quaternary ammonium compound of formula (X): wherein R0, R1, R2 and R3 is each individually an optionally substituted alkyl, alkenyl or aryl group and R includes an optionally substituted hydrocarbyl moiety having at least 5 carbon atoms.

Abstract: A quaternary ammonium compound of formula (X), wherein R0, R, R2 and R3 is each individually an optionally substituted alkyl, alkenyl or aryl group and R includes an optionally substituted hydrocarbyl moiety having at least 5 carbon atoms.

Abstract: A quaternary ammonium salt of formula wherein each of R1, R2, R3 and R4 is independently selected from an optionally substituted alkyl, alkenyl or aryl group having less than 8 carbon atoms and R5 is hydrogen or an optionally substituted hydrocarbyl group.

Abstract: A diesel fuel composition comprising a first additive (i) comprising a quaternary ammonium salt and a second additive (ii) comprising a Mannich reaction product; wherein the quaternary ammonium salt additive (i) is formed by the reaction a quaternising agent which is not an ester and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): wherein R2 and R3 are the same or different alkyl, alkenyl or aryl groups having from 1 to 22 carbon atoms; X is a bond or alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C22 alkyl group; and wherein the Mannich reaction product additive (ii) is the product of a Mannich reaction between: (d) an aldehyde; (e) an amine; and (f) a substituted phenol; wherein the phenol is substituted with at least one branched hydrocarbyl group having a molecular weight of between 200 and 3000.

Abstract: A diesel fuel composition comprising a first additive (i) comprising a quaternary ammonium salt and a second additive (ii) comprising a Mannich reaction product; wherein the quaternary ammonium salt additive (i) is formed by the reaction of a compound of formula (A): R O O R1 10 (A) and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): 15 N X R3 R2 NHR4 N X R3 R2 [O(CH2)m]nOH (B1) (B2) wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group; R1 is a C1 to C22 alkyl, aryl or alkylaryl group; wherein R2 and R3 are the same or different alkyl, alkenyl or aryl groups having from 1 to 22 carbon atoms; X is a bond or alkylene group having from 1 to 20 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C22 alkyl group; and wherein the Mannich reaction product additive (ii) is the product of a Mannich reaction between: (d) an aldehyde; (e) an amine; and25 (f) a substituted phenol; wherein the phe

Abstract: A gasoline composition comprising, as an additive, one or more quaternary ammonium salt(s) (i) formed by the reaction of a compound of formula (A): and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group; R1 is an alkyl, aryl or alkylaryl group having up to 36 carbon atoms; R2 and R3 are the same or different alkyl groups having from 1 to 36 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C36 alkyl group.

Abstract: A quaternary ammonium salt of formula wherein each of R1, R2, R3 and R4 is independently selected from an optionally substituted alkyl, alkenyl or aryl group having less than 8 carbon atoms and R5 is hydrogen or an optionally substituted hydrocarbyl group.

Abstract: A gasoline composition comprising, as an additive, one or more quaternary ammonium salt(s) (i) formed by the reaction of a compound of formula (A): and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group; R1 is an alkyl, aryl or alkylaryl group having up to 36 carbon atoms; R2 and R3 are the same or different alkyl groups having from 1 to 36 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C36 alkyl group.

Abstract: A gasoline composition comprising, as an additive, one or more quaternary ammonium salt(s) (i) formed by the reaction of a compound of formula (A): and a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (B1) or (B2): wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group; R1 is an alkyl, aryl or alkylaryl group having up to 36 carbon atoms; R2 and R3 are the same or different alkyl groups having from 1 to 36 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C36 alkyl group.

Abstract: A method of removing deposits from a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising an engine cleaning additive, wherein the engine cleaning additive is the product of a Mannich reaction between: (a) an aldehyde; (b) ammonia, hydrazine or an amine; and (c) an optionally substituted phenol; wherein the or each substituent of the phenol component (c) has an average molecular weight of less than 400.

Abstract: A diesel fuel composition comprising a quaternary ammonium salt additive which additive is formed by the reaction of (1) a quaternising agent and (2) a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and at least 1.4 molar equivalents of an amine of formula (B1) or (B2), wherein R2 and R3 are the same or different alkyl, alkenyl or aryl groups having from 1 to 22 carbon atoms; X is a bond or alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R4 is hydrogen or a C1 to C22 alkyl group.

Abstract: A quaternary ammonium compound of formula (X), wherein R0, R, R2 and R3 is each individually an optionally substituted alkyl, alkenyl or aryl group and R includes an optionally substituted hydrocarbyl moiety having at least 5 carbon atoms.

Abstract: A quaternary ammonium compound which is the reaction product of: (a) a tertiary amine having a molecular weight of less than 1000; (b) an acid-activated alkylating agent; and (c) a diacid including an optionally substituted hydrocarbyl moiety having at least (5) carbon atoms.

Abstract: A diesel fuel composition comprising, as an additive, the product of a Mannich reaction between: (a) an aldehyde; (b) an amine; and (c) a substituted phenol; wherein the phenol is substituted with at least one branched hydrocarbyl group having a molecular weight of between 200 and 3000; and wherein in the Mannich reaction used to form the additive the molar ratio of component (a) to component (b) is 2.2-1.01:1; the molar ratio of component (a) to component (c) is 1.99-1.01:1 and the molar ratio of component (b) to component (c) is 1:1.01-1.99.

Abstract: A diesel fuel composition comprising a performance enhancing additive, wherein the performance enhancing additive is the product of a Mannich reaction between: (a) an aldehyde; (b) a polyamine; and (c) an optionally substituted phenol; wherein the molar ratio of component (c) to component (b) in the reaction mixture used to prepare the performance enhancing additive is at least 1.5:1.

Abstract: A diesel fuel composition comprising a performance enhancing additive, wherein the performance enhancing additive is the product of a Mannich reaction between: (a) an aldehyde; (b) a polyamine; and (c) an optionally substituted phenol; wherein the polyamine component (b) includes the moiety R1R2NCHR3CHR4NR5R6 wherein each of R1, R2 R3, R4, R5 and R6 is independently selected from hydrogen, and an optionally substituted alkyl, alkenyl, alkynyl, aryl, alkylaryl or arylalkyl substituent.

Abstract: A method of reducing deposits in a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising a detergent additive which is not a quaternary ammonium salt or a Mannich reaction product; and a quaternary ammonium salt additive comprising the reaction product of nitrogen containing species having at least one tertiary amine group and a quaternizing agent; wherein the nitrogen containing species is selected from: (i) the reaction product of a hydrocarbyl-substituted acylating agent and a compound comprising at least one tertiary amine group and a primary amine, secondary amine or alcohol group; (ii) a Mannich reaction product comprising a tertiary amine group; and (iii) a polyalkylene substituted amine having at least one tertiary amine group.