The effect of feed on the fuel properties produced during H-ZSM-5 oligomerization of Fischer-Tropsch type feed materials has been studied. Under reaction conditions sufficient for equilibration of the carbon number distribution of the product, the isomer distribution was not equilibrated. This made the fuel properties sensitive to feed composition. The pore constraining geometry of ZSM-5 reduced branching, which improved the cetane number of the distillate, but reduced the octane number of the motor-gasoline. The distillate had a CH3/CH2 ratio of 0.6 (compared to > 2 for solid phosphoric acid catalyzed oligomerization). Density and viscosity were mainly determined by the distillation range and increased with the final boiling point of the product, with the molecular structure playing a smaller role. Carbonyl compounds in Fischer-Tropsch derived feeds were partly converted to carboxylic acids, resulting in products with higher acid content than the feed.