The subject matter of the present invention is a fuel composition which comprises —at least 85% by weight of one or more fractions of hydrocarbons having a distillation range within the range extending from 100 to 400° C. and having a paraffin content greater than or equal to 90% by weight; —at least a first additive consisting of a particular quaternary ammonium salt; and —at least a second additive consisting of a phenolic antioxidant. The subject matter of the invention is also the use of a composition of additives comprising said first and second additives, for improving at least one property of a paraffin-rich fuel composition.

The present invention provides a fuel oil composition, including: a fuel oil base oil having a sulfur element content of from 0.01 mass % to 0.50 mass %; and a calcium salicylate having a total base number of from 100 mgKOH/g to 1,200 mgKOH/g.

Use of a wax anti-settling agent (WASA), in an automotive fuel composition, for the purpose of improving the acceleration performance of an internal combustion engine into which the fuel composition is or is intended to be introduced or of a vehicle powered by such an engine.

A quaternary ammonium compound of formula (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, R.sup.5 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 R.sup.5 is hydrogen. ##STR00001##

The present disclosure provides a fuel composition that includes hydrocarbon-based fuel boiling in the gasoline or diesel range; an amine-based detergent given by formula R.sub.1—O—(CH.sub.2).sub.m—NHR.sub.2, wherein the additive is present in about 10 ppm to about 750 ppm by weight based on total weight of the fuel composition; wherein R.sub.1 is a hydrocarbylgroup having 8 to 20 carbons, R.sub.2 is hydrogen or (CH.sub.2).sub.nNH.sub.2 moiety, and wherein m, n are independently integers having a value of 3 or greater; and one or more nitrogen-containing detergent.

The present disclosure relates to a method of reducing regeneration frequency of a diesel particulate filter in a vehicle combusting diesel fuel. The method includes combusting a diesel fuel in a vehicle engine having a diesel particulate filter and wherein the diesel particulate filter requires regeneration thereof. The diesel fuel has less than about 50 ppmw of sulfur and one or more select additives to reduce a measured frequency of regeneration of the diesel particulate filter.

A quaternary ammonium salt of formula (I): (I) where in X is a linking group; Y is O, NH or NR.sup.1 wherein R.sup.1 is H or an optionally substituted hydrocarbyl group; Q.sup.+ is a moiety that includes a quaternary ammonium cation; A.sup.− is an anion; R.sup.2 is an optionally substituted alkylene group; R.sup.3 is hydrogen or an optionally substituted hydrocarbyl group; and n is 0 or a positive integer; provided that n is not 0 when R.sup.3 is hydrogen. ##STR00001##

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. ##STR00001##

The invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

The composition of the present invention related to a quaternary ammonium salt detergent and the use of such quaternary ammonium salt detergents in a fuel composition to reduce diesel injector deposits and remove or clean up existing deposits on the diesel injectors.