US Patent 7252690 Fuel composition

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.