Copper-catalysts, based on the ZSM-5 (CuZSM5) and Cuban natural Mordenite (CuMORD) zeolites have been prepared by a conventional ion-exchange method and their catalytic activity in the selective catalytic reduction (SCR) of NO was studied using ammonia in presence of H2O and SO2. A commercial catalyst SCR (CATCO) based on V2O5-WO3-TiO2, was also studied as reference. This paper presents experimental results using catalysts without the toxic vanadium and exploits a neural network based approach to predict NO, conversion efficiency of three SCR catalysts. The derived mathematical functions are integrated in a numerical model for diesel road vehicle simulation to simulate diesel vehicles equipped with such SCR catalysts. The main results indicate that despite of toxic vanadium and N2O formation, CATCO shows the better NO, conversion efficiencies. However, CuMORD does not form N2O and have better performance than the CuZSM5. The simulation results show lower level of NOx for heavy-duty and light-duty diesel vehicles compared with homologation load cycles. (C) 2008 Elsevier B.V. All rights reserved.