This study investigates the impact of two different automotive diesel fuels (one Euro3 and one Euro4) on several unregulated exhaust emissions of a Euro3 compliant passenger car. The fuels used are characterized by their different sulfur and aromatic contents. Emission measurements were conducted on a chassis dynamometer equipped with constant volume sampling (CVS) technique. The vehicle was tested on the New European Driving Cycle (NEDC) and on various steady speeds. The non-regulated pollutants examined were the individual nitrogen compounds (NO, NO2, N2O, NH3, and NOx), individual hydrocarbons (CH4, benzene, toluene, xylene, 1,3-butadiene, ethylene, total saturated and unsaturated, total aromatics and total HC), carbonyl compounds (aldehydes and ketones), PAH, and nitro-PAH. The experimental results show a significant impact of the diesel fuel type on the exhaust emissions and in several cases, the application of the Euro4 fuel increases the exhaust emissions comparing to Euro3. (C) 2012 Elsevier Ltd. All rights reserved.