Process for producing gasoline components. The process comprises feeding a fresh olefinic hydrocarbon feedstock to a reaction zone, in which its structure is first isomerized. The isomerized hydrocarbon is drawn out of the first reaction zone and conducted to a second reaction zone, where the isomerized hydrocarbon is dimerized. The dimerized reaction product is drawn out of the second reaction zone and separated from the flow in a separation zone. Because there are more isoolefins present in the dimerization unit feed, more isoolefin dimers useful as fuel components can be produced.