Nitrogen oxides and smoke are the substantial emissions for the diesel engines. The objective of this research is to assess the potential of bio-fuels by comparing it with diesel. Initially, the biofuel and diesel were taken in separate containers, then it was measured for the different proportions by volume basis and were mixed together. After 24 hours, it was used as a fuel. Experiments have been conducted with net biofuel (B100), diesel and (B80-D20 and B60-D40) type blends. Fuel undergoes good combustion and hence there is a significant improvement in performance and reduction in emissions. Similarly, I have conducted my own research work and found out results by using an CRDi engine with Jatropha oil-diesel blend. I could attain a decrease in emission levels of Smoke opacity by 20% for JD10 than diesel at IP of 400 bar. NOx emission for JD10 at 400bar has been found to be 20 ppm less than that of diesel. Better atomization of fuel is found at 600 bar IP. The usage of alternate fuels like Jatropha, Ethanol can help us move towards a greener society, help us to live emission free by inhaling pure oxygen content and can reduce the dependence on conventional fuels.