A light duty truck Renault Trafic with a naturally aspirated 2.5 l engine was equipped with ceramic DPFs of different sizes, installed at different positions along the exhaust line of the vehicle. The filters were operated on diesel fuel doped with a cerium based additive at concentration of 100 ppm in the fuel. Tests were carried out on chassis dynamometer using the urban part of the new European driving cycle and the full new European Driving cycle. Comparisons are made between the different sizes and positioning as regards both back-pressure build-up and catalytic regeneration behavior. The results show that filter regeneration was always possible at continuous low speed driving, at relatively high filter back-pressure levels (i.e. high particulate accumulation in the filter), with an effect on fuel consumption. In contrast, the New European Driving Cycle, with alternate urban and extra urban operation of the vehicle, always provides the necessary conditions for trap regeneration therefore affects neither the fuel consumption nor maximum engine power output. The paper discusses a number of engineering guidelines for the design and installation of such a system with fully passive operation on a light duty truck.