An improved process for upgrading paraffinic naphtha to high octane fuel by contacting a naphtha feedstock, such as virgin naphtha feedstock stream containing predominantly C.sub.7 -C.sub.12 alkanes and naphthenes, with solid medium pore acid zeolite cracking catalyst under low pressure selective cracking conditions effective to produce at least 10 wt % selectivity C.sub.4 -C.sub.5 isoalkene. Cracking effluent is separated to obtain a light olefinic fraction rich in C.sub.4 -C.sub.5 isoalkene and a C.sub.6 + liquid fraction of enhanced octane value containing less than 50 wt % aromatic hydrocarbons. In a multistage operation enhanced octane products are obtained by etherifying the isoalkene fraction and by contacting the C.sub.6 + normally liquid fraction with reforming catalyst under moderate reforming conditions at elevated temperature to obtain a reformate product of enhanced octane value.