A process for preparing at least two compositions suitable for production of gasoline, which process comprises: fractionating an alkylation product to produce a first cut boiling in the range 90-106.degree. C., a second cut boiling at temperature lower than said first cut, and a third cut boiling at a temperature above said first Cut, blending at least 2% by volume of said first cut with at least 5% of a component selected from at least one of a paraffin, an aromatic hydrocarbon and an olefinic hydrocarbon, said component having a boiling point of 60-160.degree. C., wherein not more than 5% of the total composition of hydrocarbon has a boiling point of more than 160.degree. C. and wherein said composition comprises less than 5% of 2,2,3-trimethylbutane or 2,2,3-trimethylpentane, to produce a first high octane unleaded gasoline composition of RON at least 97 and MON value at least 86, and incorporating said second and third cuts with said component to produce a second high octane unleaded gasoline composition of RON at least 92 and MON value at least 80.