Abstract: “India is among those tropical countries where atmospheric temperature is having very vast range i.e. from 0°C to 48°C in various regions of the country. This vast varying temperature range may not allow the engine to perform uniformly, therefore, which temperature is most suited for operating parameters of engines and will give the best performance levels. The aim of this study is to analyze the performance of a compression ignition (CI) engine using Jatropha biodiesel and its blends with diesel as fuel on changing engine temperature to obtain best performance levels. It has been tried to investigate the optimum operating temperature of engine that will deliver the best performance level. The blends of Jatropha with diesel in varying proportions (B10, B20 and B40) are prepared and are investigated in single cylinder, four stroke CI engine computerized test rig. The results obtained on engine performance parameters i.e brake power (bp), brake specific fuel consumption (bsfc) and smoke i”

Keywords: CI engine, Jatropha biosiesel, diesel, smoke intensity, operating temperature.