PME (Palm oil methyl ester) is a promising alternative fuel among biodiesels, because palm oil is the most produced feedstock and its yield is the highest among vegetable oil crops. However, PME has a serious drawback in its relatively high pour point. The aim of this investigation is to extend the range of utilization of PME by improving its low temperature fluidity. The present study used three kinds of blended fuels composed of PME/gas oil/1-butanol to show the effect of lower pour points. Neat PME has a pour point of 19 degrees C, for a PME blend with 20% PME (PME20) the pour point is -5 degrees C, and with 40 mass% 1-butanol blended into the PME20 the pour point is -10 degrees C. Using four kinds of PME/gas oil blends as the base fuels the influence of 1-butanol addition on the engine performance, combustion characteristics, and exhaust emissions of a small single cylinder DI (direct injection) diesel engine was examined. The brake thermal efficiency of the base fuels changed little when 1-butanol was added up to 40 mass%. The results also showed that at the rated output condition the smoke emissions decreased considerably with increasing 1-butanol addition ratios. (C) 2012 Elsevier Ltd. All rights reserved.