A process for the production of a high quality gasoline blending components from refinery process streams by the alkylation of light isoparaffins with olefins using an ionic liquid catalyst is disclosed. The process includes reacting a refinery stream containing isopentane and/or isobutane with a refinery stream containing ethylene and/or propylene and butylenes under alkylation conditions in the presence of a chloroaluminate ionic liquid catalyst comprising a hydrocarbyl substituted pyridinium chloroaluminate or a hydrocarbyl substituted imidazolium chloroaluminate of the general formulas A and B, respectively. ##STR00001## Where R.dbd.H, methlyl, ethyl, propyl, butyl, pentyl or hexyl group and X is a chloroaluminate, and R1 and R2=H, methyl, ethyl, propyl, butyl, pentyl or hexyl group and where R1 and R2 may or may not be the same.