Jet combustion fuel

A hydrocarbon fuel for use in a jet combustion engine comprises a distillate hydrocarbon oil and an addition of a thiophene material in an amount corresponding to 0.1 to 2 per cent of thiophene. The thiophene material may be thiophene; thiophene hydrocarbon or hydrosulphide substitution products such as thiophenedithiol and mono-t-butyl thiophene; thiophene tar, obtained as a distillation residue in the production of thiophene from the reaction products of aliphatic hydrocarbons and sulphur; or extracts of thiophene tar with hydrocarbons such as n-heptane and isooctane. The hydrocarbon fuel may be isooctane or any distillate from heavy gasolines to heavy gas oils, a fuel of kerosene boiling range being preferred. Specification 595,814 is referred to.