Aliphatic gasoline component and process to prepare said gasoline component

An aliphatic gasoline component comprising more than 90 wt % of a mixture of trimethyl substituted compounds and monomethyl substituted compounds in a weight ratio of trimethyl to monomethyl compounds of at least 0.03 and wherein the compounds may be paraffins and olefins. The invention is also directed to a process to prepare an aliphatic gasoline component by (a) contacting a Fischer-Tropsch synthesis product with a catalyst system comprising a catalyst, which catalyst comprises an acidic matrix and a large pore molecular sieve in a riser reactor at a temperature of between 450 and 650° C. at a contact time of between 1 and 10 seconds and at a catalyst to oil ratio of between 2 and 20 k.g/kg, (b) isolating from the product of step (a) a gasoline fraction and a fraction comprising iso-butane and isobutylene; (c) subjecting the iso-butane and the iso-butylene obtained in step (b) to an alkylation step to prepare a trimethyl substituted pentane, and (d) combining the gasoline fraction obtained in step (b) with the product rich in trimethyl substituted pentane as obtained in step (c).