The hydroconversion of a n-heptane-methylcyclohexane-toluene mixture representative of FCC gasoline was analyzed through a Jumped parameter reaction model that incorporates the main reaction paths and the acid/metal sites ratio of the catalyst as an explicit key parameter. The catalytic experiments were performed at relevant operating conditions using mechanical mixtures of metal/alumina+HZSM5 powders. The catalyst acid/metal sites ratio was modified by changing the type of metal and metal content. The observed main reaction paths were isomerization and cracking of n-heptane, and methylcyclohexane, and aromatic alkylation reactions. The first and last routes were the most sensitive to small changes in the catalyst acid/metal sites balance. It was found that the mathematical model reproduces well the catalytic behavior of the hydroconversion process when the acid/metal sites ratio of the catalyst is varied. (C) 2004 Published by Elsevier Ltd.