Fuel composition

Abstract

A lead-free gasoline fuel composition for improving engine performance of a spark-ignition internal combustion engine wherein the lead-free gasoline fuel composition comprises: a major amount of a gasoline base fuel and a detergent additive package wherein the detergent additive package comprises a mixture of a quaternary ammonium inner salt detergent and a Mannich base detergent, wherein the quaternary ammonium inner salt is obtained from an amine or polyamine substantially free of any free anionic species wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1: 6 to about 3: 1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1: 10 to about 1: 100.

Description

Technical Field

[0001] The present invention relates to fuel compositions containing certain fuel additives for providing enhanced engine and / or injector performance, and methods for using the fuel compositions to improve engine performance and / or injector performance. Background Art

[0002] The fuel composition for vehicles is continuously improved to strengthen the various characteristics of fuel, so as to adapt to its purposes in newer, more advanced engines (comprising gasoline intake port fuel injection engines and gasoline direct injection engines).Usually, the improvement of fuel composition focuses on other components used in improved fuel additives and fuel.For example, friction modifiers can be added to the fuel to reduce the friction and wear in the fuel delivery system of the engine.Other additives can be included to reduce the corrosion potential of the fuel or to improve the conduction characteristics.Other additives can also be blended with fuel to improve fuel economy.Engine and fuel delivery system deposits represent another problem of modern internal combustion engines, and therefore other fuel additives generally include various deposition control additives to control and / or alleviate engine deposition problems.Therefore, fuel composition generally includes the composite mixture of additives.

[0003] However, there is still a challenge when trying to balance the additive of this composite type. For example, some conventional fuel additives can be beneficial to a feature or a type of engine, but are harmful to another feature of fuel at the same time. In some cases, effective fuel additives in gasoline intake port fuel injection engines do not necessarily provide comparable performance in gasoline direct injection engines, and vice versa. In other cases, fuel additives usually require unreasonable high treatment rates to achieve the desired effect, which tends to set undesirable restrictions on the amount that can be obtained for other additives in the fuel composition. Other fuel additives tend to be expensive and / or difficult to manufacture or be incorporated in the fuel. This type of shortcoming is especially true in the case of quaternary ammonium salt fuel additives, which are usually difficult to manufacture or have high manufacturing costs and / or require a relatively high treatment rate for performance. Summary of the invention

[0004] According to the present invention, there is provided an unleaded gasoline fuel composition comprising a major amount of a base fuel and a detergent additive package, wherein the detergent additive package comprises a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is derived from an amine or polyamine substantially free of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:100.

[0005] According to the present invention, there is further provided the use of an unleaded gasoline fuel composition for improving engine and / or injector performance of a gasoline direct injection engine, wherein the unleaded gasoline fuel composition comprises a major amount of a gasoline base fuel and a detergent additive package, wherein the detergent additive package comprises a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is obtained from an amine or polyamine substantially free of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:100.

[0006] According to the present invention, there is further provided a method for improving engine performance and / or injector performance of a gasoline direct injection engine, the method comprising supplying to the engine an unleaded gasoline fuel composition comprising a major amount of a gasoline base fuel and a detergent additive package, wherein the detergent additive package comprises a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is obtained from an amine or polyamine substantially free of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:100.

[0007] The method or use of the preceding paragraph may include optional steps, features, or limitations of any combination thereof. Approaches or embodiments of the method or use may include one or more of the following: wherein the improved injector performance is one of improved fuel flow, improved fuel economy, improved engine efficiency, or a combination thereof; and / or wherein the improved injector performance is measured by one of injector pulse width, injection duration, injector flow, or a combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a graph showing the long term fuel trim (LTFT) of the inventive example and comparative examples 1 and 2. DETAILED DESCRIPTION

[0009] The unleaded gasoline fuel composition of the present invention comprises a combination of a Mannich detergent and a quaternary ammonium salt, and in particular a combination of a Mannich detergent and a hydrocarbyl-substituted quaternary ammonium inner salt, which has been found to be effective in providing improved engine and / or injector performance in gasoline direct injection (GDI) engines. Also provided herein is a method of using or burning a fuel comprising the fuel additive combination herein to achieve improved engine and / or injector performance.

[0010] The inventors have found that the unleaded gasoline fuel composition of the present invention provides improved engine and / or injector performance, including control or reduction of fuel injector deposits. The improved injector performance may also result in one or more of improved fuel flow, improved fuel economy and / or improved engine efficiency, as determined via one or more of injector pulse width, injection duration and / or injector flow.

[0011] In one aspect of the present invention, an unleaded gasoline fuel composition comprises a gasoline base fuel and a detergent additive package. The detergent additive package is typically used in a concentration of 6 PTB (23 ppmw) to 528 PTB (2000 ppmw), preferably 8 PTB (30 ppmw) to 300 PTB (1125 ppmw), more preferably 30 PTB (113 ppmw) to 250 PTB (942 ppmw) (where PTB represents pounds of additive per thousand barrels of gasoline).

[0012] The detergent additive package used herein comprises a Mannich base detergent mixture comprising a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is obtained from an amine or polyamine substantially devoid of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, preferably from about 1:4 to about 2:1, more preferably from about 1:2 to about 2:1, for example 1:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:100, preferably from about 1:20 to about 1:50, more preferably from about 1:25 to about 1:35, for example about 1:25, about 1:30 or about 1:35. Suitable Mannich base detergent mixture used herein is disclosed in US2016 / 0289584. The bag may also contain a solvent. The example of a suitable solvent includes an aromatic solvent (e.g., xylene, aromatic 100, aromatic 150, and aromatic 200), an alcohol, a petroleum distillate (e.g., gasoline), an ester, or a mixture thereof. The bag may further include one or more of a demulsifier, a corrosion inhibitor, an anti-wear additive, an antioxidant, a metal passivator, an antistatic additive, a demisting agent, an anti-knock additive, a lubricating additive, and / or a combustion improver. In one aspect, a quaternary ammonium inner salt detergent and a Mannich base detergent mixture together constitute 5%-90% of the bag.

[0013] In one embodiment herein, a suitable fuel additive package comprises (i) a Mannich base detergent mixture comprising (a) a first Mannich base detergent component derived from a diamine or a polyamine, (b) a second Mannich base detergent component derived from a monoamine, (ii) a quaternary ammonium inner salt, and (iii) optionally, a carrier fluid component selected from the group consisting of a polyether monool and a polyether polyol. The weight ratio of the first Mannich base detergent to the second Mannich base detergent in the fuel additive package ranges from about 1:6 to about 3:1, such as 1:4 to 2:1 or 1:3 to 1:1. The weight ratio of the Mannich base detergent mixture to the quaternary ammonium salt in the detergent additive package ranges from about 1:10 to about 1:100, preferably from about 1:20 to about 1:50, more preferably from about 1:25 to about 1:35, for example about 1:25, about 1:30 or about 1:35.

[0014] In another aspect of the invention, a gasoline fuel composition comprises a combination of a Mannich base detergent additive and a quaternary ammonium inner salt detergent rather than a detergent additive package. In this aspect of the invention, the Mannich base detergent additive is added to a gasoline base fuel by premixing the separate detergent additives together, optionally with one or more antiwear additives and / or one or more succinimide detergents and / or one or more carrier fluids, and then adding the premix to the gasoline base fuel; or by adding the separate detergent additive and separate antiwear additive and carrier fluid directly to the gasoline base fuel.

[0015] Mannich base detergent :

[0016] The Mannich base detergents useful in the present invention are reaction products of alkyl-substituted hydroxyaromatic compounds, aldehydes, and amines. The alkyl-substituted hydroxyaromatic compounds, aldehydes, and amines used to prepare the Mannich detergent reaction products described herein can be any such compounds known and used in the art, provided that the Mannich-based detergent comprises at least one first Mannich base detergent derived from a diamine or polyamine and at least one second Mannich base detergent derived from a dialkyl monoamine.

[0017] Representative alkyl-substituted hydroxyaromatic compounds that can be used to form the Mannich base reaction product are polypropylphenol / cresols (formed by alkylating phenol / cresol with polypropylene), polybutylphenol or polybutylcresol (formed by alkylating phenol / cresol with polybutene and / or polyisobutylene), and polybutyl-co-polypropylphenol or polybutyl-co-polypropylcresol (formed by alkylating phenol / cresol with butene and / or copolymers of butene and propylene). Other similar long chain alkylphenol / cresols can also be used. Examples include phenol / cresol alkylated with copolymers of butene and / or isobutylene and / or propylene and one or more monoolefin comonomers copolymerizable therewith (e.g., ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, etc.), wherein the copolymer molecules contain at least 50% by weight of butene and / or isobutylene and / or propylene units. The comonomers polymerized with propylene, butylene and / or isobutylene may be aliphatic and may also contain non-aliphatic groups, such as styrene, o-methylstyrene, p-methylstyrene, divinylbenzene, etc. Therefore, in any case, the resulting polymers and copolymers for forming alkyl-substituted hydroxyaromatic compounds are essentially aliphatic hydrocarbon polymers. In one embodiment of this invention, polybutylphenol or polybutylcresol (formed by alkylating phenol / cresol with polybutene) are used to form Mannich base detergents. Unless otherwise specified herein, the term "polybutene" is used in a general sense to include polymers made from "pure" or "substantially pure" 1-butene or isobutylene, and polymers made from a mixture of two or all three of 1-butene, 2-butene and isobutylene. Commercial grades of such polymers may also contain insignificant amounts of other olefins. So-called highly reactive polybutenes having a relatively high proportion of polymer molecules having terminal vinylidene groups, formed by processes such as described, for example, in US Pat. No. 4,152,499 and W. German Offenlegungsschrift 29 04 314, are also suitable for forming long-chain alkylated phenol / cresol reactants.

[0018] The alkylation of hydroxyaromatic compounds is generally carried out in the presence of an alkylation catalyst at a temperature in the range of about 50°C to about 200°C. Acidic catalysts are generally used to promote Friedel-Crafts alkylation. Typical catalysts used in commercial production include sulfuric acid, BF3, aluminum phenolate, methanesulfonic acid, cation exchange resins, acidic clays and modified zeolites.

[0019] The long chain alkyl substituents on the benzene rings of the phenolic compounds are derived from polyolefins having a number average molecular weight (MW) of about 500 Daltons to about 3000 Daltons (preferably about 500 Daltons to about 2100 Daltons), as determined by gel permeation chromatography (GPC). It is also desirable that the polydispersity (weight average molecular weight / number average molecular weight) of the polyolefins used is in the range of about 1 to about 4 (suitably about 1 to about 2), as determined by GPC.

[0020] Mannich detergents can be made from long chain alkylphenols. However, other phenolic compounds can be used, including high molecular weight alkyl-substituted derivatives of cresols, resorcinol, hydroquinone, catechol, hydroxydiphenyls, benzylphenol, phenethylphenol, naphthol, toluene naphthol, etc. Particularly suitable for preparing Mannich condensation products are polyalkylphenol and polyalkylcresol reactants, such as polypropylphenol, polybutylphenol, polypropylcresol, polyisobutylcresol and polybutylcresol, wherein the number average molecular weight of the alkyl group is from about 500 to about 2100, and the most suitable alkyl group is a polybutyl group derived from polybutene, and its number average molecular weight is in the range of about 800 Daltons to about 1300 Daltons.

[0021] The configuration of the alkyl-substituted hydroxyaromatic compound is that of a para-substituted monoalkylphenol or a para-substituted monoalkyl-ortho-cresol. However, any alkylphenol that is easy to react in the Mannich condensation reaction can be used. Therefore, the Mannich product made of an alkylphenol having only one cycloalkyl substituent or two or more cycloalkyl substituents is suitable for preparing the Mannich base detergent described herein. The long-chain alkyl substituent may contain some residual unsaturated groups, but is generally a substantially saturated alkyl group. According to the present disclosure, the long-chain alkylphenol includes cresol. Representative reactants include, but are not limited to, straight-chain, branched or cyclic alkylene monoamines and diamines or polyamines, which have at least one primary or secondary amine group with appropriate reactivity in the molecule. Other substituents such as hydroxyl, cyano, amido, etc. may be present in the amine compound. In one embodiment, the first Mannich base detergent is derived from an alkylene diamine or polyamine. Such diamines or polyamines may include, but are not limited to, polyethylene polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexyleneheptamine, heptaethyleneoctamine, octaethylenenonamine, nonaethylenedecaamine, decaethyleneundecamine, and polyamines having a structure corresponding to the formula H. 2 N-(A-NH--) n H, wherein A is a divalent ethylene and n is an integer from 1 to 10. Alkylene polyamines can be obtained by the reaction of ammonia and dihaloalkanes such as dichloroalkanes. Thus, alkylene polyamines obtained by the reaction of 2 to 11 moles of ammonia with 1 to 10 moles of dichloroalkanes having 2 to 6 carbon atoms and chlorine on different carbon atoms are suitable alkylene polyamine reactants.

[0022] In one embodiment, the first Mannich base detergent is derived from an aliphatic linear, branched or cyclic diamine or polyamine having one primary or secondary amino group and one tertiary amino group in the molecule. Examples of suitable polyamines include compounds such as N,N,N",N"-tetraalkyl-dialkylene triamine (two terminal tertiary amino groups and one central secondary amino group), N,N,N",N"-tetraalkyl trialkylene tetraamine (one terminal tertiary amino group, two internal tertiary amino groups and one terminal secondary amino group), N,N,N,N",N"-pentaalkyl trialkylene tetraamine (one terminal tertiary amino group, two internal tertiary amino groups and one terminal secondary amino group), N,N-dihydroxyalkyl-α,ω-alkylene diamine (one terminal tertiary amino group and one terminal secondary amino group), N,N,N'-trihydroxy-alkyl α,ω-alkylene diamine (one terminal tertiary amino group and one terminal secondary amino group), tris(dialkylaminoalkyl)aminoalkyl methane (three terminal tertiary amino groups and one terminal primary amino group), wherein the alkyl groups are the same or different and generally each contain no more than about 12 carbon atoms, and suitably each contain 1 to 4 carbon atoms. In one embodiment, the alkyl groups of the polyamine are methyl groups and / or ethyl groups. Thus, the polyamine reactant can be selected from N,N-dialkyl α,ω-alkylenediamines, such as those having 3 to about 6 carbon atoms in the alkylene group and 1 to about 12 carbon atoms in each alkyl group. Particularly useful polyamines are N,N-dimethyl-1-,3-propylenediamine and N-methylpiperazine.

[0023] Examples of polyamines having one reactive primary or secondary amino group that can participate in the Mannich condensation reaction and at least one hindered amino group that cannot directly participate in the Mannich condensation reaction to any appreciable extent include N-(tert-butyl)-1,3-propylenediamine, N-neopentyl-1,3-propylenediamine, N-(tert-butyl)-1-methyl-1,2-ethylenediamine, N-(tert-butyl)-1-methyl-1,3-propylenediamine, and 3,5-di(tert-butyl)aminoethyl-1-piperazine.

[0024] The second Mannich base detergent can be derived from an alkyl monoamine, which includes but is not limited to dialkyl monoamines such as methylamine, dimethylamine, ethylamine, diethylamine, propylamine, isopropylamine, dipropylamine, diisopropylamine, butylamine, isobutylamine, dibutylamine, diisobutylamine, pentylamine, dipentylamine, neopentylamine, dineopentylamine, hexylamine, dihexylamine, heptylamine, diheptylamine, octylamine, dioctylamine, 2-ethylhexylamine, di-2-ethylhexylamine, nonylamine, dinonylamine, decylamine, didecylamine, dicyclohexylamine, and the like.

[0025] Representative aldehydes for preparing Mannich base products include aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, heptaldehyde, stearaldehyde. Aromatic aldehydes that can be used include benzaldehyde and salicylaldehyde. Illustrative heterocyclic aldehydes used herein are furfural and thiophene aldehyde, etc. Also useful are reagents that produce formaldehyde such as paraformaldehyde, or formaldehyde solutions such as formalin. Particularly suitable aldehydes can be selected from formaldehyde and formalin.

[0026] The condensation reaction between the alkylphenol, the specific amine and the aldehyde can be carried out at a temperature in the range of about 40°C to about 200°C. The reaction can be carried out in bulk (without a diluent or solvent) or in a solvent or diluent. Water is released during the reaction process and can be removed by azeotropic distillation. Typically, the Mannich reaction product is formed by reacting an alkyl-substituted hydroxyaromatic compound, an amine and an aldehyde in a molar ratio of 1.0:0.5-2.0:1.0-3.0, respectively.

[0027] Suitable Mannich base detergents for use with the disclosed embodiments include those taught in U.S. Pat. Nos. 4,231,759, 5,514,190, 5,634,951, 5,697,988, 5,876,468, 6,800,103, and 10,457,884, the disclosures of which are incorporated herein by reference.

[0028] When preparing fuel composition used herein, use the mixture of Mannich base washing agent.The mixture of Mannich base washing agent comprises the first Mannich base washing agent and the second Mannich base washing agent of about 1:6 to about 3:1 weight ratio.In another embodiment, the mixture of Mannich base washing agent comprises the first Mannich base washing agent and the second Mannich base washing agent of about 1:4 to about 2:1, such as about 1:3 to about 1:1 weight ratio.Based on the gross weight of fuel composition, according to the total amount of Mannich base washing agent in gasoline fuel composition of the present disclosure can be in the scope of about 10 parts per million by weight to about 400 parts per million by weight.

[0029] The optional component of the fuel composition and / or additive package as herein described is a succinimide detergent. When added in an amount effective for this purpose, the succinimide detergent suitable for use in the various embodiments of the present disclosure can impart a dispersant effect to the fuel composition. Relative to the performance of succinimide with the first Mannich base detergent or the second Mannich base detergent, it is observed that succinimide is present in the fuel composition together with the mixed Mannich base detergent, resulting in enhanced deposition formation control.

[0030] Succinimide detergents include, for example, alkenyl succinimides comprising a reaction product obtained by reacting an alkenyl succinic anhydride acid, acid ester or lower alkyl ester with an amine containing at least one primary amine group.

[0031] Suitable succinimide base detergents for use herein include those disclosed in US 2016 / 0289584, which is incorporated herein by reference.

[0032] When succinimide detergent is present in the fuel composition / additive package herein, the weight ratio of succinimide detergent to Mannich base detergent mixture is preferably in the range of about 0.04:1 to about 0.2:1.

[0033] In another embodiment, Mannich base detergent mixture and succinimide detergent can be used together with liquid carrier or induction aid. Such carrier can be various types, such as liquid poly-alpha olefin oligomer, mineral oil, liquid poly (oxyalkylene) compound, liquid alcohol or polyol, polyolefin, liquid ester and similar liquid carrier. A mixture of two or more such carriers can be used. Suitable carrier liquids used herein include those disclosed in US2016 / 0289584, which is incorporated herein by reference.

[0034] When a carrier liquid is present, the weight ratio of carrier liquid to Mannich base detergent mixture preferably ranges from about 0.25:1 to about 1:1.

[0035] The fuel compositions and / or detergent additive packages herein may also comprise an anti-wear component which may be selected from the group consisting of hydrocarbyl amides and hydrocarbyl imides.

[0036] In one embodiment, the hydrocarbyl amide is an alkanolamide derived from diethanolamine and oleic acid. In another embodiment, the hydrocarbyl imide is a succinimide derived from polyisobutenyl succinic anhydride and ammonia. In one embodiment, the hydrocarbyl amide compound may be one or more fatty acid alkanolamide compounds.

[0037] Suitable antiwear additives for use herein include those carrier fluids disclosed in US 2016 / 0289584, which is incorporated herein by reference.

[0038] Quaternary ammonium salt :

[0039] The detergent additive package or fuel composition herein includes quaternary ammonium salts, and preferably quaternary ammonium inner salts or betaine compounds. As used herein, the term "inner salt" means containing an equal number of positively charged and negatively charged functional groups. The term "inner salt" can be used interchangeably with the term "zwitterion". As used herein, the term betaine is a zwitterion that cannot be isomerized to a fully neutral form, such as when the positive change is located on the quaternary ammonium group. The quaternary ammonium salt additive can be any alkyl-substituted quaternary ammonium inner salt (or betaine) obtained from an amine or polyamine that is substantially free of any free anionic species. For example, such additives can be made by reacting a tertiary amine of the following structure.

[0040]

[0041] Wherein each R group of above-mentioned structure is independently selected from the C2-C8 carboxylic acid, its ester, amide or salt of the alkyl group and halogen replacement containing 1 to 200 carbon atoms.In method, generally avoid being selected from the quaternizing agent of the group consisting of: alkyl-substituted carboxylic acid ester, carbonate, cyclic carbonate, phenolate, epoxide or their mixture.In one embodiment, the C2-C8 carboxylic acid, its ester, amide or salt of halogen replacement can be selected from chloro-C2-C8 carboxylic acid, bromo-C2-C8 carboxylic acid, fluorine-C2-C8 carboxylic acid and iodine-C2-C8 carboxylic acid, their ester, amide and salt.Salt can be alkali metal salt or alkaline earth metal salt selected from sodium salt, potassium salt, lithium salt, calcium salt and magnesium salt.The especially useful halogen-substituted compound for reaction is sodium salt or potassium salt of chloroacetic acid.

[0042] As used herein, the term "substantially free of free anionic species" means that the anions are mostly covalently bound to the product, so that the reaction product prepared does not contain a large amount of free anions or anions ionically bound to the product. In one embodiment, "substantially free" means a range of 0 to less than about 2 weight %, less than about 1.5 weight %, less than about 1 weight %, less than about 0.5 weight % of free anionic species or no free anionic species.

[0043] In another embodiment, tertiary amines containing monoamines and polyamines can be reacted with acetic acid, esters or other derivatives thereof substituted with halogens to provide the quaternary ammonium inner salt additives herein. Suitable tertiary amine compounds are those tertiary amine compounds with the above structure, wherein as mentioned above, each R group is independently selected from a hydrocarbyl group containing 1 to 200 carbon atoms. Each hydrocarbyl group R can independently be straight chain, branched, substituted, cyclic, saturated, unsaturated or contain one or more heteroatoms. Suitable hydrocarbyl groups can include, but are not limited to, alkyl groups, aryl groups, alkylaryl groups, arylalkyl groups, alkoxy groups, aryloxy groups, amide groups, ester groups, imide groups, etc. Any of the aforementioned hydrocarbyl groups can also contain heteroatoms, such as oxygen atoms or nitrogen atoms. Especially suitable hydrocarbyl groups can be straight or branched alkyl groups. In some embodiments, the tertiary amine can be the reaction product of a diamine or triamine with a tertiary amine and a hydrocarbyl-substituted carboxylic acid. In other embodiments, some representative examples of amine reactants that can react to produce compounds of the present disclosure include, but are not limited to, trimethylamine, triethylamine, tri-n-propylamine, dimethylethylamine, dimethyllaurylamine, dimethyloleylamine, dimethylstearylamine, dimethyleicosylamine, dimethyloctadecylamine, N,N-dimethylpropylenediamine, N-methylpiperidine, N,N'-dimethylpiperazine, N-methyl-N-ethylpiperazine, N-methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, pyridine, triethanolamine, triisopropanolamine, methyldiethanolamine, dimethylethanolamine, lauryldiisopropanolamine, stearyldiethanolamine, Dioleylethanolamine, dimethylisobutanolamine, methyldiisooctanolamine, dimethylpropyleneamine, dimethylbutylamine, dimethyloctenylamine, ethyldidodecenylamine, dibutyleicosylamine, triethylenediamine, hexamethylenetetramine, N,N,N'N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'-tetraethyl-1,3-propylenediamine, methyldicyclohexylamine, 2,6-lutidine, dimethylcyclohexylamine, C10-C30-alkyl or alkenyl substituted amidopropyldimethylamine, C12-C200-alkyl or alkenyl substituted succinic acid carbonyldimethylamine, etc. In an embodiment, a suitable quaternary ammonium inner salt additive may be an inner salt of oleylamidopropyldimethylamino or oleyldimethylamine.

[0044] If the amine contains only primary or secondary amino groups, it may be necessary to alkylate at least one of the primary or secondary amino groups to a tertiary amino group prior to reaction with the halogen-substituted C2-C8 carboxylic acid, its ester, amide or salt. In one embodiment, the alkylation of the primary and secondary amines or mixture with the tertiary amine may be fully or partially alkylated to a tertiary amine. It may also be necessary to take due account of the hydrogen on the nitrogen and provide a base or acid as required (e.g., alkylation until the tertiary amine requires removal (neutralization) of hydrogen (protons) from the alkylated product). If an alkylating agent such as an alkyl halide or dialkyl sulfate is used, the product of the alkylation of the primary or secondary amine is a protonated salt and requires a base source to release the amine for further reaction.

[0045] The halogen-substituted C2-C8 carboxylic acid, its ester, amide or salt for preparing the quaternary salt additive can be derived from mono-, di- or trichloro-carboxylic acid, bromo-carboxylic acid, fluoro-carboxylic acid or iodo-carboxylic acid, their ester, amide or salt, which is selected from the group consisting of: halogen-substituted acetic acid, propionic acid, butyric acid, isopropionic acid, isobutyric acid, tert-butyric acid, valeric acid, heptanoic acid, octanoic acid, halogenated methyl benzoic acid and their isomers, esters, amides and salts. The salt of the carboxylic acid may include an alkali metal salt or an alkaline earth metal salt or an ammonium salt, including but not limited to Na salts, Li salts, K salts, Ca salts, Mg salts, triethylammonium salts and triethanolammonium salts of the halogen-substituted carboxylic acid. Particularly suitable halogen-substituted carboxylic acids, their esters or salts may be selected from chloroacetic acid or its ester and sodium chloroacetate or potassium chloroacetate. Relative to the amount of the tertiary amine reactant, the amount of the halogen-substituted C2-C8 carboxylic acid, its ester, amide or salt may be in the molar ratio range of about 1:0.1 to about 0.1:1.0.

[0046] In other embodiments, the inner salt of the mixture herein can be prepared according to the aforementioned procedures and can include, but is not limited to, (1) formula R"-NMe 2 CH 2 COO, wherein R" is a C1 to C30 or substituted amide group; (2) fatty amide substituted inner salts; and (3) hydrocarbon substituted imide, amide or ester inner salts, wherein the hydrocarbon group has 8 to 40 carbon atoms. Particularly suitable inner salts can be selected from the group consisting of: polyisobutenyl substituted succinimide, succinic acid diamide and succinic acid diester inner salts; C8-C40 alkenyl substituted succinimide, succinic acid diamide and succinic acid diester inner salts; oleyl amidopropyl dimethylamino inner salts; and oleyl dimethylamino inner salts.

[0047] In another embodiment, the quaternary ammonium inner salt of the fuel additive and fuel herein is an inner salt or betaine compound having the structure of Formula II below:

[0048]

[0049] wherein R and R' of the above structure are independently an alkylene linker having 1 to 10 carbon atoms (1 to 3 carbon atoms in other methods); 8 is a saturated alkylene group, an unsaturated olefin group, or a linear, branched or cyclic hydrocarbon group or an optionally substituted or unsubstituted C12-C100 hydrocarbon group, or an aryl group or an optionally substituted aryl group (in one method, R 8 is a C8 to C20 hydrocarbon group); each R 9 are independently a linear or branched C1 to C4 alkyl group; and R 10 is a hydrogen atom or a C1 to C4 alkyl group. The inner salt of Formula II may also be substantially free of free anionic species as discussed above.

[0050] In another embodiment, the quaternary ammonium salt additive includes a compound of Formula II above, wherein R is a propylene linker, R' is a methylene linker, and R 8 is a C8 to C20 hydrocarbon group, each R 9 is a methyl group, and R 10 is hydrogen. In other embodiments, the quaternary ammonium salt inner salt is selected from oleyl amidopropyl dimethylamine inner salt or oleyl dimethylamine inner salt. In some embodiments, such additives may be substantially free of free anionic species as described above.

[0051] An exemplary reaction scheme for preparing a quaternary ammonium inner salt is shown in the exemplary method of Reaction Scheme 1 below; of course, other methods for preparing the first quaternary ammonium salt additive described herein may also be utilized:

[0052]

[0053] In the above reaction scheme, R 8 As described above, or in one method, is an alkyl group, such as a C12 to C100 hydrocarbon group; R and R' are independently an alkylene linker having 1 to 10 carbon atoms; each R 9 are independently an alkyl group or a linear or branched C 1 To C 4 group; and R'' is an alkyl group or hydrogen.

[0054] The fuel additive package herein may include from about 1 wt % to about 15 wt % of a quaternary ammonium inner salt, from about 1 wt % to about 10 wt % of a quaternary ammonium inner salt, or from about 1.5 wt % to about 5 wt % of a quaternary ammonium inner salt (based on the total active weight of the quaternary ammonium salt in the fuel additive). When blended into a gasoline fuel, the fuel composition may include from about 0.1 ppmw to about 10 ppmw of active quaternary ammonium inner salt, from about 0.3 ppmw to about 5 ppmw of active quaternary ammonium inner salt, or from about 1 ppmw to about 3 ppmw of active quaternary ammonium inner salt based on the weight of the fuel composition.

[0055] fuel :

[0056] The fuel composition of this paper comprises the base fuel of major amount.As used herein, the term " major amount " preferably means greater than 50% volume / volume relative to base fuel, more preferably greater than 60% volume / volume, even more preferably greater than 70% volume / volume, especially greater than the level of 80% volume / volume.In a preferred embodiment of this paper, " major amount " of base fuel means greater than 90% volume / volume based on total fuel composition, more preferably greater than 95% volume / volume, even more preferably greater than 98% volume / volume.If liquid fuel composition of the present invention contains gasoline base fuel, then this liquid fuel composition is a gasoline fuel composition.Gasoline can be any gasoline applicable to spark ignition (gasoline) type internal combustion engine known in the art, including automobile engines and other types of engines, such as off-road and aviation engines.Gasoline used as base fuel in liquid fuel composition of the present invention can also be conveniently referred to as "base gasoline".

[0057] Gasoline generally comprises a mixture of hydrocarbons boiling in the range of 25°C to 230°C. (EN-ISO 3405), the optimum range and distillation curve generally varying according to the climate and season of the year. The hydrocarbons in gasoline may be obtained by any means known in the art, conveniently the hydrocarbons may be obtained in any known manner from straight run gasoline, synthetically produced aromatic mixtures, thermally or catalytically cracked hydrocarbons, hydrocracked petroleum fractions, catalytically reformed hydrocarbons or mixtures of these.

[0058] The specific distillation curve, hydrocarbon composition, research octane number (RON) and motor octane number (MON) of the gasoline are not critical.

[0059] Conveniently, the gasoline may have a Research Octane Number (RON) of at least 80, for example in the range of 80 to 110, preferably the gasoline will have a RON of at least 90, for example in the range of 90 to 110, more preferably the gasoline will have a RON of at least 91, for example in the range of 91 to 105, even more preferably the gasoline will have a RON of at least 92, for example in the range of 92 to 103, even more preferably the gasoline will have a RON of at least 93, for example in the range of 93 to 102, and most preferably the gasoline will have a RON of at least 94, for example in the range of 94 to 100 (EN 25164); the gasoline may conveniently have a Motor Octane Number (MON) of at least 70, for example in the range of 70 to 110, preferably the gasoline will have a MON of at least 75, for example in the range of 75 to 105, more preferably the gasoline will have a MON of at least 80, for example in the range of 80 to 100, most preferably the gasoline will have a MON of at least 82, for example in the range of 82 to 95 (EN 25164). 25163).

[0060] Typically, gasoline comprises components selected from one or more of the following group: saturated hydrocarbons, olefins, aromatic hydrocarbons and oxygenated hydrocarbons. Conveniently, gasoline may comprise a mixture of saturated hydrocarbons, olefins, aromatic hydrocarbons and optionally oxygenated hydrocarbons.

[0061] Typically, the olefin content of gasoline is in the range of 0 volume % to 40 volume % based on gasoline (ASTM D1319); preferably, the olefin content of gasoline is in the range of 0 volume % to 30 volume % based on gasoline, and more preferably, the olefin content of gasoline is in the range of 0 volume % to 20 volume % based on gasoline.

[0062] Typically, the aromatic content of gasoline is in the range of 0 volume % to 70 volume % based on gasoline (ASTM D1319), for example, the aromatic content of gasoline is in the range of 10 volume % to 60 volume % based on gasoline; preferably, the aromatic content of gasoline is in the range of 0 volume % to 50 volume % based on gasoline, for example, the aromatic content of gasoline is in the range of 10 volume % to 50 volume % based on gasoline.

[0063] The benzene content of the gasoline is at most 10% by volume, more preferably at most 5% by volume, in particular at most 1% by volume, based on the gasoline. The gasoline preferably has a low or ultra-low sulfur content, for example at most 1000 ppmw (parts per million by weight), preferably not more than 500 ppmw, more preferably not more than 100 ppmw, even more preferably not more than 50 ppmw and most preferably not more than even 10 ppmw.

[0064] The gasoline also preferably has a low total lead content, such as at most 0.005 g / l, and is most preferably unleaded, having no lead compounds added thereto (ie, unleaded).

[0065] When gasoline contains oxygenated hydrocarbons, at least a portion of the non-oxygenated hydrocarbons will be replaced with oxygenated hydrocarbons. The oxygen content of gasoline can be up to 35 wt % (EN 1601) (e.g., ethanol itself), based on gasoline. For example, the oxygen content of gasoline can be up to 25 wt %, preferably up to 10 wt %. Conveniently, the oxygenated compound concentration will have a minimum concentration selected from any one of 0 wt %, 0.2 wt %, 0.4 wt %, 0.6 wt %, 0.8 wt %, 1.0 wt % and 1.2 wt %, and a maximum concentration selected from any one of 5 wt %, 4.5 wt %, 4.0 wt %, 3.5 wt %, 3.0 wt % and 2.7 wt %.

[0066] Examples of oxygenated hydrocarbons that can be blended into gasoline include alcohols, ethers, esters, ketones, aldehydes, carboxylic acids and their derivatives, and oxygen-containing heterocyclic compounds. Preferably, the oxygenated hydrocarbons that can be blended into gasoline are selected from alcohols (such as methanol, ethanol, propanol, 2-propanol, butanol, tert-butyl alcohol, isobutanol and 2-butanol), ethers (preferably ethers containing 5 or more carbon atoms per molecule, such as methyl tert-butyl ether and ethyl tert-butyl ether) and esters (preferably esters containing 5 or more carbon atoms per molecule); a particularly preferred oxygenated hydrocarbon is ethanol.

[0067] When oxygenated hydrocarbons are present in the gasoline, the amount of oxygenated hydrocarbons in the gasoline can vary over a wide range. For example, gasolines containing a larger proportion of oxygenated hydrocarbons are currently commercially available in countries such as Brazil and the United States, such as ethanol itself and E85, and gasolines containing a smaller proportion of oxygenated hydrocarbons, such as E10 and E5. Thus, the gasoline may contain up to 100% by volume of oxygenated hydrocarbons. Also included herein is E100 fuel as used in Brazil. Preferably, the amount of oxygenated hydrocarbons present in the gasoline is selected from one of the following amounts: up to 85% by volume; up to 70% by volume; up to 65% by volume; up to 30% by volume; up to 20% by volume; up to 15% by volume; and up to 10% by volume, depending on the desired final formulation of the gasoline. Conveniently, the gasoline may contain at least 0.5%, 1.0% by volume, or 2.0% by volume of oxygenated hydrocarbons.

[0068] Examples of suitable gasolines include gasolines having an olefin content of 0 to 20 vol% (ASTM D1319), an oxygen content of 0 to 5 wt% (EN 1601), an aromatics content of 0 to 50 vol% (ASTM D1319) and a benzene content of up to 1 vol%.

[0069] Also suitable for use herein are gasoline blending components that may be derived from biological sources. Examples of such gasoline blending components can be found in WO2009 / 077606, WO2010 / 028206, WO2010 / 000761, European Patent Application Nos. 09160983.4, 09176879.6, 09180904.6, and U.S. Patent Serial No. 61 / 312,307.

[0070] Although not critical to the present invention, in addition to the above-mentioned essential Mannich detergent and quaternary ammonium detergent, the base gasoline or gasoline composition of the present invention can conveniently include one or more optional fuel additives. The concentration and property of the optional fuel additive that can be included in the base gasoline or gasoline composition for the present invention are not critical. The non-limiting example of the fuel additive of the suitable type that can be included in the base gasoline or gasoline composition for the present invention includes antioxidant, corrosion inhibitor, anti-wear additive or surface improver, flame speed additive, detergent, defogging agent, anti-knock additive, metal deactivator, valve seat shrinkage protective agent compound, dye, solvent, carrier fluid, diluent and marker. The example of suitable such additive is generally described in U.S. Patent number 5,855,629.

[0071] Conveniently, the fuel additive may be blended with one or more solvents to form an additive concentrate, and the additive concentrate may then be mixed with the base gasoline or gasoline composition of the present invention.

[0072] The (active matter) concentration of any optional additive present in the base gasoline or gasoline composition of the invention is preferably up to 1 wt.%, more preferably in the range of 5 to 2000 ppmw, advantageously in the range of 300 to 1500 ppmw, such as 300 to 1000 ppmw.

[0073] Example

[0074] The following examples are illustrations of exemplary embodiments of the present disclosure. In these examples and elsewhere in this application, unless otherwise indicated, all ratios, parts and percentages are by weight. It is contemplated that these examples are presented for illustrative purposes only and are not intended to be used to limit the scope of the invention disclosed herein. The specifications of the base fuels in the examples are shown in Table 1 below.

[0075] Table 1: Fuel specifications .

[0076]

[0077] Example 1

[0078] Oleamidopropyl dimethyl ammonium betaine quaternary ammonium inner salt can be prepared by the method described in US Pat. No. 8,894,726 (Example 3 of the present invention), which is incorporated herein by reference.

[0079] Example 2

[0080] The two Mannich detergents and the quaternary ammonium salt were blended into the base fuel described in Table 1 at the treatment rates listed in Table 2 below. The first Mannich detergent was prepared from highly reactive polyisobutylene cresol, diamine and formaldehyde according to known methods (see, e.g., US 6,800,103, which is incorporated herein by reference). The second Mannich detergent was prepared using the same method but using a monoamine. The quaternary ammonium inner salt was oleylamidopropyl dimethylammonium from Example 1.

[0081] Table 2

[0082]

[0083] A series of three dirty / clean (DU / CU) tests were conducted to evaluate the effects of the fuels from Table 2 on fuel injector deposits in vehicles equipped with gasoline direct injection engines (GDI). All tests were conducted with the base fuel from Table 1 during the dirty (DU) and clean (CU) phases of the respective tests. The fuels were tested to evaluate the ability of each type of additive, Mannich detergent mixture, and quaternary ammonium salt to improve injector performance by reducing injector deposits in a GDI engine, both individually (Comparative Examples 1 and 2) and together (Inventive Examples).

[0084] The base fuel was previously evaluated in a bench engine to determine its propensity to foul or foul injectors. Fouling levels can be measured indirectly using engine control management (ECM) algorithm parameters such as changes in injector pulse width or long term fuel trim (LTFT). The test bed used for this evaluation was a gasoline direct injection GM LHU engine using the RIFT method as outlined in Smith, S. and Imoehl, W., “Measurement and Control of Fuel Injector Deposits in Direct Injection Gasoline Vehicles,” SAE Technical Paper 2013-01-2616, 2013, doi: 10.4271 / 2013-01-2616 and / or Shanahan, C., Smith, S. and / or Sears, B., “A General Method for Fouling Injectors in Gasoline Direct Injection Vehicles and the Effects of Deposits on Vehicle Performance,” SAE Int. J. Fuels Lubr. 10(3):2017, doi: 10.4271 / 2017-01-2298, both of which are incorporated herein by reference.

[0085] To accelerate the DU phase of the base fuel, a combination of di-tert-butyl disulfide (DTBDS 406.1 ppmw) and tert-butyl hydroperoxide (TBHP, 286 ppmw) was added to the base fuel to provide fouling in the range of 5%-12% over the time allotted for the DU phase. The fouling percentage in the GM engine based on injector pulse width was calculated as follows:

[0086]

[0087] A series of three GDI CU deposition tests were conducted to demonstrate the removal of deposits that have been formed in the fuel injector during the contamination (DU) phase. The base fuels in Table 1 treated with DTBDS and TBHP were used for DU. This carrier-based test procedure uses a 2008 Pontiac Solstice carrier mounted on a chassis dynamometer. This procedure was first listed in DuMont, R. et al., "Test and Control of Fuel Injector Deposits in Direct Injected Spark Ignition Vehicles," SAE Technical Paper 2009-01-2641, 2009, doi: 10.4271 / 2009-01-2641. It consists of a 48-hour DU cycle, with LTFT continuously monitored to maintain a stoichiometric air / fuel ratio. After the DU cycle is completed, the fuel is replaced with one of the additive formulations described in Table 2, and then a 48-hour CU cycle is operated. The percentage increase in LTFT during the DU cycle and the subsequent percentage decrease during the CU cycle is one parameter used to evaluate the fouling or cleaning effect of the fuel candidates at the treatment rates listed in Table 3 below, which demonstrates 62% cleaning (CU) in 48 hours for the inventive example. CU is calculated as follows:

[0088]

[0089] Table 3

[0090]

[0091] As shown in Table 3 above, the inventive examples exhibit improved injector cleaning relative to the comparative examples. For the combination of the first and second Mannich detergents with the quaternary ammonium salt, the CU% is 62%, while the two Mannich detergents alone provide 6.2% GDI CU and quaternary ammonium salt 28.1%. Figure 1 is a graphical representation of the data in Table 3. Figure 1 Long term fuel trim (LTFT) of the inventive example and comparative examples 1 and 2 are shown.

[0092] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless expressly and unambiguously limited to one referent. Thus, for example, reference to "an antioxidant" includes two or more different antioxidants. As used herein, the term "comprising" and its grammatical variations are intended to be non-limiting, such that recitation of items in a list does not exclude other like items that can be substituted or added to the listed items.

[0093] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers and other numerical values ​​used in this specification and the claims indicating quantities, percentages or ratios should be understood as being modified in all cases by the term "about". Therefore, unless otherwise indicated to the contrary, the numerical parameters listed in the following specification and the appended claims are approximate values, which may vary depending on the desired properties sought to be obtained by the present disclosure. At a minimum, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0094] It is to be understood that each component, compound, substituent or parameter disclosed herein is to be interpreted as disclosed for use alone or in combination with one or more of each and every other component, compound, substituent or parameter disclosed herein.

[0095] It is further understood that each range disclosed herein is interpreted as a disclosure of each specific value having the same number of significant figures within the disclosed range. Thus, for example, a range of 1 to 4 is interpreted as an explicit disclosure of the values ​​1, 2, 3, and 4, as well as any range of such values.

[0096] It is further understood that for the same component, compound, substituent or parameter, each lower limit of each scope disclosed herein is interpreted as disclosed in combination with each upper limit of each scope disclosed herein and each specific value in each scope. Therefore, the disclosure is interpreted as the disclosure of all scopes obtained by combining each lower limit of each scope with each upper limit of each scope or with each specific value in each scope, or by combining each upper limit of each scope with each specific value in each scope. That is, it should be further understood that any scope between the endpoint values ​​in a wide range is also discussed herein. Therefore, the scope of 1 to 4 also means the scope of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0097] In addition, the specific amounts / values ​​of components, compounds, substituents or parameters disclosed in this specification or examples should be interpreted as disclosing the lower or upper limit of the range, and can therefore be combined with any other lower or upper limit of the range or specific amount / value of the same component, compound, substituent or parameter disclosed elsewhere in this application to form the range of that component, compound, substituent or parameter.

Claims

1. An unleaded gasoline fuel composition for improving the engine performance of a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises: The main amount of gasoline base fuel and Detergent additive packs, wherein the detergent additive package comprises a mixture of a quaternary ammonium inner salt detergent and a Mannich base detergent, wherein the quaternary ammonium inner salt is obtained from an amine or polyamine substantially devoid of any free anionic species, wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or a polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and The weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture is in the range of about 1:10 to about 1:

100.

2. The unleaded gasoline fuel composition of claim 1, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent ranges from about 1:1 to about 1:

3.

3. An unleaded gasoline fuel composition according to claim 1 or 2, wherein the unleaded gasoline fuel composition comprises from about 23 ppm to 2000 ppm by weight of the detergent additive package.

4. An unleaded gasoline fuel composition according to any one of claims 1 to 3, wherein the first Mannich base detergent and the second Mannich base detergent are derived from polyisobutenyl substituted hydroxyaromatics, and wherein the polyisobutenyl groups have a molecular weight in the range of 500 Daltons to 1000 Daltons as determined by gel permeation chromatography.

5. The gasoline fuel additive package of claim 4, wherein the polyisobutenyl-substituted hydroxyaromatic is a polyisobutenyl-substituted phenol or cresol.

6. The gasoline fuel additive package of claim 5, wherein the polyisobutenyl-substituted hydroxyaromatic is a polyisobutenyl-substituted cresol.

7. The unleaded gasoline fuel composition according to any one of claims 1 to 6, wherein the quaternary ammonium inner salt has a structure of formula II wherein R and R' are independently an alkylene linker having 1 to 10 carbon atoms; R8 is a C12 to C100 alkylene, alkene or hydrocarbyl group or an aryl group or an optionally substituted aryl group; each R9 is independently a straight or branched C1 to C4 alkyl group; and R 10 is a hydrogen atom or a C1 to C4 alkyl group.

8. The gasoline fuel additive package according to any one of claims 1 to 7, wherein the package further comprises one or more of demulsifiers, corrosion inhibitors, antiwear additives, antioxidants, metal deactivators, antistatic additives, dehazers, antiknock additives, lubricity additives, polyether monools or polyether polyol carrier fluids, and combustion improvers.

9. Use of an unleaded gasoline fuel composition for improving engine and / or injector performance of a gasoline direct injection engine, wherein the unleaded gasoline fuel composition comprises a major amount of a gasoline base fuel and a detergent additive package, wherein the detergent additive package comprises a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is derived from an amine or polyamine substantially devoid of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:

100.

10. A method for improving engine performance and / or injector performance of a gasoline direct injection engine, the method comprising supplying to the engine an unleaded gasoline fuel composition comprising a major amount of a gasoline base fuel and a detergent additive package, wherein the detergent additive package comprises a quaternary ammonium inner salt detergent and a Mannich base detergent mixture, wherein the quaternary ammonium inner salt is derived from an amine or polyamine substantially devoid of any free anionic species, and wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a diamine or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the weight ratio of the quaternary ammonium inner salt detergent to the Mannich base detergent mixture ranges from about 1:10 to about 1:100.

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