Abstract: Polymeric fuels are produced from saturated C.sub.4 hydrocarbons by a process comprising:(A) dehydroisomerizing a gas mixture comprising predominantly of n-butane and hydrogen in a catalytic reactor containing a catalyst (a) of platinum supported on alumina, whose surface is coated with silica, and, optionally, a solid acidic catalyst (b) selected from the group consisting of alumina, whose surface is coated with silica, and Boralite B, with an effluent being obtained which comprises a mixture of predominantly of unreacted n-butane, butenes and isobutene, all of which components of the mixture have a carbon atom content less than 5;(B) separating the mixture of olefins and parafins from hydrogen and aromatic byproducts; and(C) oligomerizing said mixture in the presence of a catalyst consisting of amorphous silica-alumina gel, as determined by X-rays, having a silica:alumina molar ratio within the range of 30:1 to 500:1, with a surface area of from 500 to 1000 m.sup.