EP3736317A1 - Fuel composition - Google Patents

Abstract

Fuel composition containing in a larger amount a petrol with a sulfur content of a maximum of 150 ppm by weight, and in a smaller amount at least one petrol additive with detergent effect or with valve seat wear-inhibiting effect, this petrol additive at least one hydrophobic hydrocarbon residue with a number average molecular weight of 85 to 20,000 and has at least one polar grouping, the fuel composition also having a content of at least one lower alkanol of about 5 to 75% by volume.

Description

The present invention relates to a fuel composition containing in a larger amount a special low-alkanol-containing gasoline and in a smaller amount selected gasoline additives.

Carburettors and intake systems of gasoline engines, but also injection systems for fuel metering, are increasingly burdened by contamination caused by dust particles in the air, unburned hydrocarbon residues from the combustion chamber and the crankcase ventilation gases fed into the carburetor.

These residues shift the air-fuel ratio when idling and in the lower partial load range, so that the mixture becomes leaner, the combustion less complete and, in turn, the proportions of unburned or partially burned hydrocarbons in the exhaust gas increase and gasoline consumption increases.

It is known that in order to avoid these disadvantages, fuel additives are used to keep valves and carburetors or injection systems of gasoline engines clean (see, for example: M.Rossenbeck in catalysts, tensides, mineral oil additives, ed. J. Falbe, U. Hasserodt, p. 223, G. Thieme Verlag, Stuttgart 1978 ).

Furthermore, the problem of valve seat wear arises in older types of gasoline engines when operated with unleaded gasoline. To counteract this, valve seat wear-inhibiting additives based on alkali or alkaline earth metal compounds have been developed.

For trouble-free use, modern gasoline engines require fuels with a complex property profile that can only be guaranteed in combination with corresponding gasoline additives. Such petrol usually consist of a complex mixture of chemical compounds and are characterized by physical parameters. The interaction between gasoline fuels and corresponding additives is, however, in need of improvement in the known fuel compositions with regard to the cleaning or keeping clean and the valve seat wear-inhibiting effect.

The object of the present invention was therefore to find a more effective gasoline-gasoline fuel additive composition. In particular, more effective additive formulations should be found.

Accordingly, a fuel composition has been found which contains a large amount of a gasoline fuel with a maximum sulfur content of 150 wt has number average molecular weight (MN) of 85 to 20,000 and at least one polar moiety, and wherein the fuel composition also has a content of at least one lower alkanol of about 5 to 75% by volume.

1. (a) Mono- oder Polyaminogruppen mit bis zu 6 Stickstoffatomen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat,
2. (b) Nitrogruppen, ggf. in Kombination mit Hydroxylgruppen,
3. (c) Hydroxylgruppen in Kombination mit Mono- oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat,
4. (d) Carboxylgruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen,
5. (e) Sulfonsäuregruppen oder deren Alkalimetall- oder Erdalkalimetallsalzen,
6. (f) Polyoxy-C2- bis C4-alkylengruppierungen, die durch Hydroxylgruppen, Mono-oder Polyaminogruppen, wobei mindestens ein Stickstoffatom basische Eigenschaften hat, oder durch Carbamatgruppen terminiert sind,
7. (g) Carbonsäureestergruppen,
8. (h) aus Bernsteinsäureanhydrid abgeleitete Gruppierungen mit Hydroxy- und/oder Amino- und/oder Amido- und/oder Imidogruppen und
9. (i) durch Mannich-Umsetzung von substituierten Phenolen mit Aldehyden und Mono- oder Polyaminen erzeugte Gruppierungen

The polar grouping is selected from:

1. (a) Mono- or polyamino groups with up to 6 nitrogen atoms, with at least one nitrogen atom having basic properties,
2. (b) nitro groups, possibly in combination with hydroxyl groups,
3. (c) hydroxyl groups in combination with mono- or polyamino groups, with at least one nitrogen atom having basic properties,
4. (d) carboxyl groups or their alkali metal or alkaline earth metal salts,
5. (e) sulfonic acid groups or their alkali metal or alkaline earth metal salts,
6. (f) Polyoxy-C2- to C4-alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, at least one nitrogen atom having basic properties, or by carbamate groups,
7. (g) carboxylic ester groups,
8. (h) groups derived from succinic anhydride with hydroxyl and / or amino and / or amido and / or imido groups and
9. (i) Groups produced by the Mannich reaction of substituted phenols with aldehydes and mono- or polyamines

The lower alkanol used according to the invention is preferably a straight-chain or branched, saturated C ₁ -C ₆ mono- or diol, in particular a C ₁ -C ₃ monoalkanol, such as methanol, ethanol, n- or i-propanol, or a mixture of several of these alkanols.

The alkanol content, based on the total volume of the fuel composition, is a maximum of 75% by volume, e.g. B. 5 to 75 vol .-%, preferably 10 to 65 vol .-%, in particular 20 to 55 vol .-%, such as. B. 30-40% by volume or 40-50% by volume.

The content of other alcohols and ethers in petrol is usually relatively low. Typical maximum contents are 7% by volume for tert-butanol, 10% by volume for isobutanol and 15% by volume for ethers with 5 or more carbon atoms in the molecule.

The aromatic content of the gasoline is preferably a maximum of 40% by volume, in particular a maximum of 38% by volume. Preferred ranges for the aromatic content are from 20 to 42% by volume, in particular from 25 to 40% by volume.

The sulfur content of the gasoline is preferably a maximum of 100 ppm by weight, in particular a maximum of 50 ppm by weight. Preferred ranges for the sulfur content are 0.5 to 150 ppm by weight, in particular 1 to 100 ppm by weight.

In a preferred embodiment, the petrol has an olefin content of a maximum of 21% by volume, preferably a maximum of 18% by volume, in particular a maximum of 10% by volume. Preferred ranges for the olefin content are from 6 to 21% by volume, in particular from 7 to 18% by volume.

In a further preferred embodiment, the petrol has a benzene content of a maximum of 1.0% by volume, in particular a maximum of 0.9% by volume. Preferred ranges for the benzene content are 0.5 to 1.0% by volume, in particular 0.6 to 0.9% by volume.

In a further preferred embodiment, the gasoline has an oxygen content of at most 2.7% by weight, preferably from 0.1 to 2.7% by weight, in particular from 1.0 to 2.7% by weight, in particular from 1.2 to 2.0% by weight.

Particularly preferred is a gasoline which, at the same time, has an aromatic content of at most 38 vol.%, An olefin content of at most 21 vol.%, A sulfur content of at most 50 wt. Ppm, a benzene content of at most 1.0 vol Has an oxygen content of 1.0 to 2.7% by weight.

The above percentages by volume for olefin, benzene, aromatic and oxygen content are each based on the volume of the mineral gasoline component, ie without additives and without alkanol.

The summer vapor pressure of the gasoline is usually a maximum of 70 kPa, in particular 60 kPa (in each case at 370C).

The research octane number ("RON") of gasoline is usually 90 to 100. A common range for the corresponding engine octane number ("MOZ") is 80 to 90.

The specified specifications are determined using customary methods (DIN EN 228).

The hydrophobic hydrocarbon radical in the petrol additives, which ensures sufficient solubility in the fuel, has a number-average molecular weight (Mn) of 85 to 20,000, in particular 113 to 10,000, especially from 300 to 5000. As a typical hydrophobic hydrocarbon radical, especially in In connection with the polar groups (a), (c), (h) and (i), the polypropenyl, polybutenyl and polyisobutenyl radicals, each with Mn = 300 to 5000, in particular 500 to 2500, especially 750 to 2250, come in Consideration.

The following may be mentioned as individual petrol additives with a detergent effect or with a valve seat wear-inhibiting effect.

Additives containing mono- or polyamino groups (a) are preferably polyalkene mono- or polyalkene polyamines based on polypropene or highly reactive (ie with predominantly terminal double bonds - mostly in the alpha and beta positions) or conventional (ie with predominantly central double bonds) or polybutene Polyisobutene with Mn = 300 to 5000. Such additives based on highly reactive polyisobutene, which are obtained from polyisobutene, which can contain up to 20% by weight of n-butene units, by hydroformylation and reductive amination with ammonia, monoamines or polyamines such as dimethylaminopropylamine , Ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine can be prepared, in particular from the EP-A 244 616 known. If the production of the additives is based on polybutene or polyisobutene with predominantly central double bonds (mostly in the beta and gamma position), the production route is by chlorination and subsequent amination or by oxidation of the double bond with air or ozone to form carbonyl or Carboxyl compound and subsequent amination under reductive (hydrogenating) conditions. For the amination, the same amines can be used here as above for the reductive amination of the hydroformylated highly reactive polyisobutene. Corresponding additives based on polypropene are particularly in the WO-A 94/24231 described.

Further preferred additives containing monoamino groups (a) are the hydrogenation products of the reaction products of polyisobutenes with an average degree of polymerization P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as in particular in WO-A 97/03946 are described.

Further preferred additives containing monoamino groups (a) are the compounds obtainable from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the amino alcohols, as in particular in DE-A 196 20 262 are described.

Additives containing nitro groups, optionally in combination with hydroxyl groups, (b) are preferably reaction products of polyisobutenes with an average degree of polymerization of P = 5 to 100 or 10 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen, as in particular in WO-A 96/03367 and WO-A 96/03479 are described. These reaction products are usually mixtures of pure nitropolyisobutanes (e.g. alpha, beta-dinitropolyisobutane) and mixed hydroxynitropolyisobutanes (e.g. alpha-nitro-beta-hydroxypolyisobutane).

Hydroxyl groups in combination with additives containing mono- or polyamino groups (c) are, in particular, reaction products of polyisobutene epoxides, obtainable from polyisobutene having predominantly terminal double bonds with Mn = 300 to 5000, with ammonia, mono- or polyamines, as they are in particular in EP-A 476 485 are described.

Carboxyl groups or their alkali metal or alkaline earth metal salts (d) containing additives are preferably copolymers of C ₂ -C ₄₀ olefins with maleic anhydride with a total molecular weight of 500 to 20,000, the carboxyl groups of which are wholly or partly to the alkali metal or alkaline earth metal salts and a remaining Rest of the carboxyl groups are reacted with alcohols or amines. Such additives are in particular from EP-A 307 815 known. Such additives are mainly used to prevent valve seat wear and can, as in WO-A 87/01126 be wrote, can be used with advantage in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Additives containing sulfonic acid groups or their alkali metal or alkaline earth metal salts (s) are preferably alkali metal or alkaline earth metal salts of an alkyl sulfosuccinate, as it is in particular in US Pat EP-A 639 632 is described. Such additives are mainly used to prevent valve seat wear and can be used with advantage in combination with conventional fuel detergents such as poly (iso) butenamines or polyetheramines.

Additives containing polyoxy-C ₂ - to C ₄ -alkylene groups (f) are preferably polyethers or polyetheramines, which are obtained by reacting C ₂ - to C ₆₀ -alkanols, C ₆ - to C ₃₀ -alkanediols, mono- or di-C ₂ -C ₃₀ -alkylamines, C ₁ -C ₃₀ -alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines are available. Such products are particularly popular in EP-A 310 875 , EP-A 356 725 , EP-A 700 985 and US-A 4,877,416 described. In the case of polyethers, such products also have carrier oil properties. Typical examples are tridecanol or isotridecanol butoxylates, isononylphenol butoxylates and polyisobutenol butoxylates and propoxylates and the corresponding reaction products with ammonia.

Additives containing carboxylic ester groups (g) are preferably esters of mono, di or tricarboxylic acids with long-chain alkanols or polyols, in particular those with a minimum viscosity of 2 mm2 / s at 100 ° C, as in particular in DE-A 38 38 918 are described. Aliphatic or aromatic acids can be used as mono-, di- or tricarboxylic acids, while long-chain representatives with, for example, 6 to 24 carbon atoms are particularly suitable as ester alcohols or polyols. Typical representatives of the esters are adipates, phthalates, isophthalates, terephthalates and trimellitates of iso-octanol, iso-nonanol, iso-decanol and iso-tridecanol. Such products also meet carrier oil properties.

Groups derived from succinic anhydride and having additives containing hydroxyl and / or amino and / or amido and / or imido groups (h) are preferably corresponding derivatives of polyisobutenylsuccinic anhydride, which are obtained by reacting conventional or highly reactive polyisobutene with Mn = 300 to 5000 with maleic anhydride thermal routes or via the chlorinated polyisobutene are available. Of particular interest here are derivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylene pentamine. Such gasoline additives are in particular in US-A-4,849,572 described.

Additives containing groups (i) produced by the Mannich reaction of substituted phenols with aldehydes and mono- or polyamines are preferably reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or dimethylaminopropylamine. The polyisobutenyl-substituted phenols can be made from conventional or highly reactive polyisobutene with Mn = 300 date to 5000. Such "polyisobutene Mannich bases" are particularly in the EP-A 831 141 described.

For a more precise definition of the individual listed gasoline additives, express reference is made here to the disclosures of the above-mentioned prior art documents.

The fuel composition according to the invention can also contain other customary components and additives. Carrier oils without a pronounced detergent effect are primarily to be mentioned here, for example mineral carrier oils (base oils), in particular those of the viscosity class "Solvent Neutral (SN) 500 to 2000", and synthetic carrier oils based on olefin polymers with Mn = 400 to 1800, above all based on polybutene or polyisobutene (hydrogenated or non-hydrogenated), of polyalphaolefins or polyinternalolefins.

As solvents or diluents (if additive packages are provided), aliphatic and aromatic hydrocarbons, e.g. Solvent naphtha.

Other common additives are corrosion inhibitors, for example based on ammonium salts of organic carboxylic acids that tend to form films or on heterocyclic aromatics for non-ferrous metal corrosion protection, antioxidants or stabilizers, for example based on amines such as p-phenylenediamine, dicyclohexylamine or derivatives thereof or on phenols such as 2,4-di -tert-butylphenol or 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid, demulsifiers, antistatic agents, metallocenes such as ferrocene or methylcyclopentadienyl manganese tricarbonyl, lubricity additives such as certain fatty acids, alkenylsuccinic acid esters, bis (hydroxyalkyl) acetamines, fatty amines or castor oil and dyes (markers). Sometimes amines are also added to lower the pH of the fuel.

For the fuel composition according to the invention, combinations of the described gasoline with a mixture of gasoline additives with the polar grouping (f) and corrosion inhibitors and / or lubricity improvers based on carboxylic acids or fatty acids, which can be present as monomeric and / or dimeric species, are also particularly suitable. Typical mixtures of this type contain polyisobutenamines in combination with alkanol-initiated polyethers such as tridecanol or isotridecanol butoxylates or propoxylates, polyisobutene amines in combination with alkanol-initiated polyether amines such as tridecanol or isotridecanol butoxylate-ammonia reaction products in combination with alkanol-initiated polyethanol-ammonia reaction products and alkanol-initiated polyethanol-ammonia reaction products such as isotidecanol ca like tridecanol or Isotridecanol butoxylates or propoxylates, in each case together with the mentioned corrosion inhibitors or lubricity improvers.

The petrol additives mentioned with the polar groups (a) to (i) and the other components mentioned are metered into the petrol and develop their effect there. The components or additives can be added to the petrol individually or as a previously prepared concentrate ("additive package").

The gasoline additives mentioned with the polar groups (a) to (i) are usually added to the gasoline in an amount of 1 to 5000 ppm by weight, in particular 5 to 3000 ppm by weight, especially 10 to 1000 ppm by weight . The other components and additives mentioned are, if desired, added in the usual amounts.

With the fuel composition according to the invention, surprisingly, with significantly less detergent or valve seat wear-inhibiting agent, the same cleaning or keeping clean or valve seat wear-inhibiting effect can be achieved as with comparable fuel compositions without the addition of low alkanol. Furthermore, when the same amounts of detergent or valve seat wear-inhibiting agent are used, the fuel composition according to the invention surprisingly results in a significantly better cleaning or keeping clean or valve seat wear-inhibiting effect compared to conventional fuel compositions.

Furthermore, the fuel composition according to the invention also has advantages in that fewer deposits are formed in the combustion chamber of the Otto engine and that less additive is introduced into the engine oil via the fuel dilution.

1. i) die Verwendung eines Niedrigalkanols in schwefelarmen Ottokraftstoffen zur Verbesserung der Wirkung eines Additivs mit Detergenswirkung oder mit ventilsitzverschleißhemmender Wirkung gemäß obiger Definition;
2. ii) ein Verfahren zur Verbesserung der Additiv-Wirkung eines Additivs mit Detergenswirkung oder mit ventilsitzverschleißhemmender Wirkung gemäß obiger Definition in schwefelarmen Ottokraftstoffen, wobei man den Ottokraftstoff mit einer wirksamen Menge eines Niedrigalkohols versetzt;
3. iii) die Verwendung einer Kombination aus Niedrigalkohol und wenigstens einem Additiv mit Detergenswirkung oder mit ventilsitzverschleißhemmender Wirkung gemäß obiger Definition zur Verringerung von Brennraumablagerungen und/oder zur Verringerung von Ablagerungen im Einlasssystem eines Ottomotors.
4. iv) die Verwendung einer Kombination aus Niedrigalkohol und Additiv mit Ventilsitzverschleißhemmender Wirkung gemäß obiger Definition als Ventilsitzverschleißhemmer für Ottokraftstoffe.

Further objects of the invention relate to

1. i) the use of a lower alkanol in low-sulfur petrol to improve the effect of an additive with a detergent effect or with a valve seat wear-inhibiting effect as defined above;
2. ii) a method for improving the additive effect of an additive with a detergent effect or with a valve seat wear-inhibiting effect as defined above in low-sulfur petrol, wherein the petrol is mixed with an effective amount of a lower alcohol;
3. iii) the use of a combination of lower alcohol and at least one additive with a detergent effect or with a valve seat wear-inhibiting effect according to the above Definition for reducing combustion chamber deposits and / or for reducing deposits in the intake system of a gasoline engine.
4. iv) the use of a combination of low alcohol and additive with valve seat wear-inhibiting effect as defined above as a valve seat wear inhibitor for petrol.

The following examples are intended to explain the invention in more detail without, however, restricting it.

Examples:

A commercial additive package comprising 60% by weight of detergent additive polyisobutenamine (Mn = 1000 g / mol) and 32% by weight of carrier oil (tridecanol etherified with 22 units of butylene oxide) was used as the gasoline fuel additive.

The gasoline fuels used were those listed below with the corresponding specification given, with OK 1 (for parameters see Table 1) representing a typical commercially available fuel. Table 1 specification OK 1 Aromatic content [vol .-%] 39.8 Paraffin content [% by volume] 47.7 Olefin content [% by volume] 12.5 Sulfur content [ppm by weight] 35 Density [15 ° C] [kg / m ³ ] 743.6 Start of boiling 34.5 ° C 10% volume 50 ° C 50% volume 85 ° C 90% volume 150.5 ° C End of boiling 189.0 ° C OK 2 = OK 1 + 10 vol% EtOH
OK 3 = OK 1 + 50 vol% EtOH

Manufacture of fuel compositions

• Example 1 (comparative experiment)
  150 or 200 mg additive package were dissolved in 1 kg OK 1 according to Table 1.
• Example 2 (according to the invention)
  Example 1 was repeated, but using OK 2 instead of OK 1.
• Example 3 (according to the invention)
  Example 1 was repeated, but using OK 3 instead of OK 1.

Technical application studies Example 4

Gasoline fuels according to Examples 1 to 3 were examined with regard to their influence on the inlet system cleanliness (IVD) and on the combustion chamber deposits (TCD). This was done with the help of engine tests that were carried out in test bench tests with a Mercedes-Benz M102 E engine in accordance with CEC F-05-A-93. The IVD values for fuels with and without additives are summarized in Table 2 below.

Furthermore, the amount of combustion chamber deposits (TCD) for each of the four cylinders of the engine was determined in the same test series. The respective mean value is also given in Table 2. The procedure for determining the TCD value was analogous to CEC F-20-A-98. Table 2 fuel OK 1 OK 2 OK 3 Additive amount [mg / kg] 0 150 200 0 150 200 0 150 200 IVD ¹⁾ [mg / valve] 269 85 23 293 98 15th 239 31 3 TCD ²⁾ [mg / cylinder] 1778 1864 1807 1677 1668 1713 1056 1248 764 ¹⁾ Intake Valve Deposits
²⁾ Total Combustion Deposits

As can be seen from Table 2, when larger amounts of ethanol (i.e.> 10%) are added to the petrol, a surprisingly low formation of valve or combustion chamber (cylinder) deposits is observed.

Claims (12)

Fuel composition containing in a larger amount a petrol with a sulfur content of a maximum of 150 ppm by weight, and in combination a smaller amount of at least one petrol additive with detergent effect or with valve seat wear-inhibiting effect, this petrol additive at least one hydrophobic hydrocarbon residue with a number average molecular weight (MN) of 85 to 20,000 and at least one polar grouping, and at least one lower alkanol in a proportion of about 5 to 75% by volume, this combination of additives reducing the deposits in the intake system of a gasoline engine, determinable according to CEC F-05-A -93, effected. The fuel composition of claim 1, wherein the polar moiety is selected from: (a) Mono- or polyamino groups with up to 6 nitrogen atoms, with at least one nitrogen atom having basic properties, (b) nitro groups, possibly in combination with hydroxyl groups, (c) hydroxyl groups in combination with mono- or polyamino groups, with at least one nitrogen atom having basic properties, (d) carboxyl groups or their alkali metal or alkaline earth metal salts, (e) sulfonic acid groups or their alkali metal or alkaline earth metal salts, (f) Polyoxy-C2- to C4-alkylene groups which are terminated by hydroxyl groups, mono- or polyamino groups, at least one nitrogen atom having basic properties, or by carbamate groups, (g) carboxylic ester groups, (h) groups derived from succinic anhydride with hydroxyl and / or amino and / or amido and / or imido groups and (i) Groups produced by the Mannich reaction of substituted phenols with aldehydes and mono- or polyamines. Fuel composition according to claim 2, containing as a petrol additive with polar groups (a) polyalkene mono- or polyalkene polyamines based on polypropene, polybutene or polyisobutene with Mn = 300 to 5000;
containing as a petrol additive with polar groups (b) reaction products of polyisobutenes with an average degree of polymerization of P = 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen;
Containing as a gasoline additive with polar groups (c) reaction products of polyisobutene epoxides, obtainable from polyisobutene having predominantly terminal double bonds with Mn = 300 to 5000, with ammonia, mono- or polyamines;
containing as a petrol additive with polar groups (d) copolymers of C ₂ -C ₄₀ olefins with maleic anhydride with a total molecular weight of 500 to 20,000, the carboxyl groups of which are wholly or partly to the alkali metal or alkaline earth metal salts and a remainder of the carboxyl groups with alcohols or amines are reacted;
containing as petrol additive with polar groups (e) alkali metal or alkaline earth metal salts of an alkyl sulfosuccinate;
containing as a petrol additive with polar groups (f) polyethers or polyetheramines, obtainable by reacting C ₂ -C ₃₀ alkanols, C ₆ -C ₆₀ alkanediols, mono- or di-C ₂ -C ₃₀ -alkylamines, C ₁ -C _30- alkylcyclohexanols or C ₁ -C ₃₀ -alkylphenols with 1 to 30 mol of ethylene oxide and / or propylene oxide and / or butylene oxide per hydroxyl group or amino group and, in the case of the polyetheramines, by subsequent reductive amination with ammonia, monoamines or polyamines;
Containing as petrol additive with polar groups (g) esters of mono-, di- or tricarboxylic acids with long-chain alkanols or polyols;
containing as a petrol additive with polar groups (h) derivatives of polyisobutenylsuccinic anhydride, obtainable by reacting conventional or highly reactive polyisobutene with Mn = 300 to 5000 with maleic anhydride by thermal means or via the chlorinated polyisobutene; or
containing as a petrol additive with polar groups (i) reaction products of polyisobutene-substituted phenols with formaldehyde and mono- or polyamines. Fuel composition according to one of Claims 1 to 3, containing a petrol with an olefin content of at most 21% by volume based on the volume of the non-additized lower alkanol-free petrol. Fuel composition according to one of Claims 1 to 4, containing a petrol with a benzene content of a maximum of 1.0% by volume based on the volume of the non-additized lower alkanol-free petrol. Fuel composition according to one of Claims 1 to 5, containing a petrol with an oxygen content of at most 2.7% by weight based on the volume of the non-additized lower alkanol-free petrol. Fuel composition according to one of Claims 1 to 6, containing a petrol with an aromatic content of at most 42% by volume based on the volume of the non-additized lower alkanol-free petrol. Fuel composition according to Claims 1 to 7, containing the petrol additives with the polar groups (a) to (i) in an amount of 1 to 5000 ppm by weight. Use of a lower alkanol in low-sulfur petrol to improve the effect of an additive with a detergent effect or with a valve seat wear-inhibiting effect as defined in claim 1. Method for improving the additive effect of an additive with detergent effect or with valve seat wear-inhibiting effect according to the definition in claim 1 in low-sulfur petrol, wherein the petrol is mixed with an effective amount of a lower alcohol. Use of a combination of lower alcohol and at least one additive with detergent effect or with valve seat wear-inhibiting effect according to the definition in claim 1 for reducing combustion chamber deposits and / or for reducing deposits in the intake system of a gasoline engine. Use of a combination of low alcohol and additive with valve seat wear-inhibiting effect according to the definition in claim 1 as a valve seat wear inhibitor for gasoline fuels.