The temperature dependence of the USHY + HZSM-5 zeolites mixing effect on the catalytic properties for the n-heptane transformation is analysed; several mixture compositions were tested at 350, 400 and 450 degreesC. The observed activities and product selectivities for the mixtures were compared to the predicted ones based on the pure zeolite tests assuming its relative contributions to the product yields and conversion with no mechanistic interactions. The most important detected synergism in the product selectivities, which is the increased C-4 products ramification, is reduced with the temperature rising.