Diesel engine 26.12 kW was used to test Jatropha biodiesel and its blends. A pilot plant was designed and built for biodiesel production from different vegetable
oils and used for this study. Five biodiesel ratio were tested and compared with
 diesel fuel. The engine performance was tested under different loads (10, 12.5 and 17.5 kW). The percent of specific fuel consumption increased from 2 to 20 % for B0 to B100 fuels. The brake thermal efficiency for biodiesel and its blends was found to be slightly higher than that of diesel fuel at tested load conditions. The exhaust gas temperature increased with increase in load and amount of diesel. The highest exhaust gas temperature was observed as 370 ºC for B100 among the three load conditions. The diesel gas exhaust temperature was observed as 420 ºC at the highest load. The CO₂ emission was higher than biodiesel fuel B100 by about 11.5% at the highest load. The carbon monoxide reduction by biodiesel was 14, 21 and 12 percent at 10, 12.5 and 17.5 kW load conditions respectively. The NOx emissions from biodiesel was increased by 15, 16 and 17 percent higher than that of the diesel at 10, 12.5 and 17.5 kW load conditions respectively.