In this study, an experimental investigation of particle size distribution emission over performance of transient conditions in a high speed diesel engine fuelled with diesel, biodiesel and Fischer Tropsch fuels have been assessed. Six fuels with different properties have been tested in a 4-cylinder light-duty diesel engine typically used for European passenger cars. The cycle used in this study was the New European Driving Cycle (NEDC) and each test was carried out after a stabilization warming period in order to avoid cold start effects. A comparative analysis between nucleation and accumulation particle mode concentration, particle size distributions and a geometric mean diameter calculation are presented in this paper. In this sense, a reduction in the range of particle diameter emitted and a decrease in accumulation particle mode concentration with Fischer Tropsch fuel during the EUDC were found. In contrast, all biofuels used show an increase of particle number concentration in nucleation-mode during the urban cycles (ECE-15) related to combustion damage at low load conditions. Finally, an increase in the sulfur content diesel fuel leads to an increase in the geometric mean diameter of particle size distribution related to the increase in accumulation particle concentration during the entire cycle. (C) 2014 Elsevier Ltd. All rights reserved.