Palm oil biodiesel is one of the renewable/biofuels produced in Indonesia. Biodiesel has hygroscopic properties, so it can lead to changes in the physical and chemical properties of the fuel. This study aims to determine the effect of stored high-speed diesel fuel (namely: Dexlite) and biodiesel from palm oil on fuel properties, performance, and emissions of single-cylinder diesel engines. Both fuels were stored for 3 months. Properties testing includes water content, calorific value, density, and viscosity. Engine performance tests include thermal efficiency, power, and fuel consumption at low load (500,1000,1500 W) and a constant speed of 2500 rpm. The results of 3 months of stored biodiesel properties showed that water content, density, and viscosity increased by 18.35%, 0.29%, and 2.31%, respectively, on the other hand, the heating decreased by 0.59%. In addition, thermal efficiency, power, and smoke emission decreased by 5.69%, 0.85%, and 17.6%, respectively.