Advances in biodiesel, emulsified diesel and artificial chemical additives are driven by consumer demand to save energy and reduce emissions from diesel engines. However, the effect of emulsified bio-solution/palm-biodiesel/diesel blends in diesel engines has not been assessed. Experimental results in this work demonstrate that the emulsified bio-solution/palm-biodiesel/diesel blends have the advantage in saving energy and reducing emissions of both polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) from diesel engines. When comparing with PO (premium diesel fuel as base fuel), E16P20 fuel (16 vol% bio-solution + 20 vol% palm-biodiesel + 64 vol% PO, an additional 1 vol% surfactant) saved 12.4% fuel consumption and reduced emissions of PM by 90.1%, total PAHs by 69.3%, and total BaPeq (benzo[a]pyrene equivalent concentration) by 69.6%. Emulsified palm-biodiesel with bio-solution can be considered as a clean and alternative fuel. (C) 2010 Elsevier Ltd. All rights reserved.