Relating to fuels

A process for the preparation of a gasoline fuel formulation comprising blending together at least 0.01% v/v tricyclene, at least 30% v/v a gasoline base fuel, and (iii) at least 1% v/v ethanol.

A fuel component premix, suitable for inclusion in a gasoline fuel formulation, the premix comprising tricyclene and one or more components selected from biofuels and oxygenates, wherein the concentration of the tricyclene and the one or more components in the premix is selected to achieve a final concentration of at least 0.01% v/v tricyclene and at least 1% v/v of the one or more components when the premix is blended with a gasoline base fuel.

A method of operating an internal combustion engine, and/or a vehicle which is driven by an internal combustion engine, said method comprising introducing into a combustion chamber of the engine a gasoline fuel formulation comprising at least 0.01% v/v tricyclene and at least 1% v/v a biofuel component or oxygenate, and operating the engine under a condition to increase the octane number, reduce the vapour pressure, modify one or more distillation properties, increase the energy content, or reduce the elastomer damaging effects of the formulation compared with operating using a gasoline composition without the tricyclene.

A gasoline fuel formulation comprising (i) at least 0.01% v/v tricyclene, (ii) at least 30% v/v a gasoline base fuel, and (iii) at least 1% v/v of ethanol.