Biodiesel from Citrullus lanatus was blended with petro-diesel, thereby forming blends of different percentages, 5%, 10%, 15%, 20%, and 25% denoted as B5, B10, B15, B20, and B25 respectively. The physico-chemical properties such as specific gravity, calorific value, cetane number, kinematic viscosity, flash point, Sulphur contents, copper strip corrosion, colour index, pour point and cloud point of each of these biodiesel with blends and pure diesel (B0) were determined. Most of the physico-chemical properties were found to be within the American Society for Testing and Materials’-ASTM standards for biodiesel. All the fuel samples are consistent with the ASTM standards with regards to viscosity and specific gravity except B100 which are slightly above the American Society for Testing and Materials standard with very insignificant values of 0.09 and 0.018 mm2/s respectively. Therefore, the blends could be a better option to be used on compression ignition-CI engines for the improvement of quality of atomization, combustion, fuel droplets and air-fuel mixing. The calorific values of the biodiesel and blends were all within the ASTM standard with B20 value slightly below that of pure diesel; similarly, the flash point of the pure biodiesel and its blends were above the pure diesel value but falls within the ASTM range. The fuel is safe to handle during storage, because it cannot easily spark when exposed to flame and hence they are recommended for use in the CI engines. The pour points of all the fuel samples conform to the ASTM standards. The cetane numbers are all greater than that of pure diesel and conforms to ASTM standards. The biodiesel will be having shortest possible ignition delay when they burn in the CI engines.
