Abstract: This invention is a fuel composition having a sulphur content of ?50 ppm by weight and comprising ?50 ppm by weight of at least one fused polycyclic aromatic compound which has at least one hetero-atom selected from O and N either (a) as a heterocyclic group, or, (b) as an exocyclic group in which the hetero-atom is attached either directly or through one other carbon atom to a ring carbon atom wherein the fused polycyclic aromatic compound is substituted on at least one of its ring carbon atoms by a C1-C4 alkyl group. These compounds are capable of improving the antiwear and lubricity properties of a low sulphur fuels, especially diesel fuels, when compared with the performance of the same fuel in the absence of such compounds.

Abstract: This invention relates to a diesel fuel composition having enhanced lubricity, said composition comprising a major amount of a diesel fuel as base fuel blended with a minor amount of a nitrogen rich fraction characterised in that the nitrogen rich fraction is derived from a source material selected from (i) a solvent extract of a solid or semi-solid natural fossil, or, (ii) a refinery process stream or blend, the sulphur to nitrogen atom ratio in the nitrogen rich fraction being less than 4. The nitrogen rich fraction has an absolute nitrogen content of at least 1000 ppm by weight and this fraction is (re)blended with the base fuel is no more than 1% by weight of the total fuel composition. Methods of separating, recovering and reblending such naturally occurring nitrogen compounds can be installed or retrofitted at existing refinery and crude oil processing facilities without any substantial increase in production costs.

Abstract: A fuel composition comprising gasoline having a sulphur content of less than 10 ppm by weight and an aromatic content of less than 25% by volume, characterized in that said composition comprises at least 5% by volume of olefins and is substantially free of any ethers. The fuel composition so formed has reduced emissions and improved fuel economy. The emissions from such compositions can be further reduced by incorporating therein a small amount of ethanol.

Abstract: This invention provides a fuel composition having a sulphur content of not more than 50 ppm by weight and comprising at least 50 ppm based on the total weight of the fuel composition of at least one fused polycyclic aromatic compound which comprises at least one exocyclic group containing nitrogen wherein the nitrogen is attached directly to a ring carbon atom. Specific examples of such compounds include 1-amino naphthalene, 1,8-diaminonaphthalene, or 5-aminoindole, 2-(2-aminophenyl)indole and 8-aminoquinoline. These compounds are capable of improving the antiwear and lubricity properties of a low sulphur fuel when compared with that of the same fuel in the absence of such compounds.

Abstract: This invention is a fuel composition having a sulphur content of ≦50 ppm by weight and comprising ≧50 ppm by weight of at least one fused polycyclic aromatic compound which has at least one hetero-atom selected from O and N either (a) as a heterocyclic group, or, (b) as an exocyclic group in which the hetero-atom is attached either directly or through one other carbon atom to a ring carbon atom wherein the fused polycyclic aromatic compound is substituted on at least one of its ring carbon atoms by a C1-C4 alkyl group. These compounds are capable of improving the antiwear and lubricity properties of a low sulphur fuels, especially diesel fuels, when compared with the performance of the same fuel in the absence of such compounds.

Abstract: This invention relates to a fuel composition comprising (i) a low sulphur fuel having a sulphur content of less than 30 ppm, a bromine number of less than 10 and an ultraviolet absorbance at 319 nm is below 0.15 and (ii) an effective amount of an ashless friction reducing additive which is a fatty acid having 10-30 carbon atoms or a derivative thereof. The fuel of the specified characteristics shown improved response to the friction reducing additive in respect of its lubricity performance.

Abstract: A fuel composition comprising gasoline having a sulphur content of less than 10 ppm by weight and an aromatic content of less than 25% by volume, characterized in that said composition comprises at least 5% by volume of olefins and is substantially free of any ethers. The fuel composition so formed has reduced emissions and improved fuel economy. The emissions from such compositions can be further reduced by incorporating therein a small amount of ethanol.