Gasoline fuel composition suitable for use in an internal combustion engine comprising: (a) Fischer-Tropsch derived naphtha at a level from 2 to 20% v/v; (b) at least one aromatic octane booster present at a level of 0.75 to 8% v/v or less; and (c) a gasoline base fuel; wherein the gasoline fuel composition comprises 40% v/v or less of aromatics. In a preferred embodiment, the Research Octane Number (RON) of the gasoline fuel composition is increased while maintaining the aromatic content of the gasoline fuel composition at a level of 40% v/v or less, based on the gasoline fuel composition.