New attractive technologies can be designed in the field of light olefins dimerization (C-3-C-5) in order to obtain products useful as gasoline blending components; the technologies are characterized both by low investment costs and by high product quality. Isobutene dimerization is a powerful alternative to MTBE production whenever the use of the latter will be forbidden in gasoline. Also the dimerization of iso-amylenes and propylene, when properly designed, can give products (both the olefins and the corresponding hydrogenated derivatives) characterized by very high octane numbers. More in general all these technologies can help to debottleneck the FCC downstream when enhanced olefins production is achieved by means of new FCC catalysts and processes.