In this study, regulated, unregulated exhaust emissions and fuel consumption with diesel fuel and palm-based biodiesel blends at proportions of 5%, 20% and 40% (v/v) have been investigated. A Euro 3 compliant light duty vehicle was tested on a chassis dynamometer over the new European driving cycle (NEDC) and the non-legislated Athens driving cycle (ADC). The experimental results showed that the addition of biodiesel increased NO, emissions. This increase was more significant with the use of B20 over both cycles (13.7% and 23.2% over the NEDC and ADC, respectively). Biodiesel addition resulted to increases in CO emissions with the highest increase being 11.78% for B20 over NEDC and 11.62% for B40 over ADC. HC emissions increased with biodiesel over the NEDC, while over the ADC the addition of biodiesel led to reductions with the highest being with the use of B40 (about 26.47%). The same observation holds for PM emissions. Over the ADC the most beneficial reduction was in the order of 50% for the B40. CO(2) emissions and fuel consumption followed similar patterns. B20 led to increases up to 6.16% and 2.94% in fuel consumption over NEDC and ADC, respectively. Some PAH compounds demonstrated an increase with biodiesel, while nitro-PAHs decreased with most of them being almost undetectable. Most carbonyl emissions decreased with biodiesel. (C) 2008 Elsevier Ltd. All rights reserved.