Provided are octane enhancing additives and methods that improve a liquid fuel composition's octane rating. A liquid fuel composition may comprise a liquid fuel and an octane enhancing additive. The octane enhancing additive may comprise an indoline compound with a bicyclic ring structure, wherein the indoline compound comprises a six-membered aromatic ring and a five-membered aliphatic ring that share a carbon-carbon aromatic bond. The five-membered aliphatic ring may be heterocyclic and may comprise a nitrogen positioned in an alpha position to the six-membered aromatic ring.

This disclosure relates to winterized pour point depressant compositions for petroleum fluids. Such compositions exhibit stability and are flowable at temperatures down to as low as 47 C., without the need for further dilution.

The present invention relates to the use of at least one, optionally alkylated diarylamine in a fuel or a fuel additive for cleaning the combustion chamber of an internal combustion engine, in particular of a motor vehicle engine. A further aspect relates to a method for cleaning the combustion chamber of an internal combustion engine during the operation of the internal combustion engine by burning a fuel, wherein the fuel contains a fuel additive comprising at least one, optionally alkylated diarylamine.

The present invention relates to the use of at least one, optionally alkylated diarylamine in a fuel or a fuel additive for cleaning the combustion chamber of an internal combustion engine, in particular of a motor vehicle engine. A further aspect relates to a method for cleaning the combustion chamber of an internal combustion engine during the operation of the internal combustion engine by burning a fuel, wherein the fuel contains a fuel additive comprising at least one, optionally alkylated diarylamine.

A fuel additive for fuel formulations comprising calcium sulfonates in an amount effective to limit or eliminate valve seat recession in engines utilizing such fuel formulations. The fuel additive may also include a detergent, particularly in an amount to enhance the VSR limiting effect of the calcium sulfonates. Also included are fuel formulations containing calcium sulfonates in a concentration effective to limit vale seat recession in engines utilizing the fuel formulations. Methods for treating VSR in piston engines are also provided.

A quaternary ammonium compound of formula (I): (I) wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group, X is a linking group, R.sup.4 is an optionally substituted alkylene group, R5 is hydrogen or an optionally substituted alkyl, alkenyl or aryl group, and n is 0 or a positive integer, provided that n is not 0 when R5 is hydrogen.

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The invention relates to novel methods for preparing N-methyl-p-toluidine for the use thereof as additive for aviation fuel, and to specific catalysts for these methods.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a dicarbonyl to thereby obtain a diimine, which is reduced to obtain mixtures comprising the antidegradant compound.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a dicarbonyl to thereby obtain a diimine, which is reduced to obtain mixtures comprising the antidegradant compound.

Described are preferred compositions for a motor fuel. Such motor fuels may be particularly well suited for use in the motor of an aircraft. In particular, compositions of the present disclosure may comprise 50-75 wt % isooctane/alkylates, 20-40 wt % ETBE, 0-3 wt % isobutane, and 0-5 wt % aromatics. The present disclosure describes a full spectrum of unleaded fuels with various motor octane (MON) values.