Abstract: Experimental work was conducted to evaluate the effect of using n-butanol (normal butanol) in conventional diesel fuel biodiesel blends on the engine performance parameter of a single cylinder direct injection compression ignition engine with the engine working at different three engine loads. A blend of biodiesel and diesel fuel known as B20 (20% biodiesel and 80% diesel in volume) was prepared, and then n-butanol was added to B20 at a volume percent of 5%,10%,15% and 20% (denoted as B5,B10,B15 and B20, respectively). The performance parameters evaluated include thermal efficiency, brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC). Results were compared with the neat diesel. The blended biodiesel is being injected to cylinder and tested up to 20% blended biodiesel. The experiment ensures that up to 20% biodiesel blended with diesel can be used without any modification in the diesel engine and enhancement of combustion, FC, BSFC, efficiency and the over all performance of the engine.