ABSTRACT Globally petro diesel prices increasing rapidly in covid-19 season also. Extracting biodiesel oil from root vegetable oils has one of the great opportunity to use as fuel in internal combustion engines. Past three or four decades researchers concentrated on single biodiesel and its blend with diesel as alternate fuel for internal combustion engines. There is lot of research need to be conduct on bio dual fuels. The current research focusing on to run the diesel engine with the mixture of two biodiesels and diesel blends as a test fuel. The performance and exhaust gas emissions of the diesel, jatropha and mustard biodiesel fuel blends studied conducting the experiments in a single cylinder, direct injection, water-cooled with constant engine speed of 1500 rpm. All the observations of dual biodiesel blends recorded and compared with the diesel fuel. The test fuels emissions carbon monoxide (CO), carbon dioxide (CO2); nitrogen oxide and smoke opacity were nearer values to the diesel fuel. The brake thermal efficiency (BTE) is higher in MJD-1 (Mustard oil 5%, Jatropha biodiesel 5% and Diesel 90%) compare to all other test fuels and less 1.6% of diesel fuel at higher brake power (BP) rates. At higher levels of BP the specific fuel consumption (SFC) maximum for MJD-5 (Mustard oil 40%, Jatropha biodiesel 40% and Diesel 90%) test fuel it is 25.58% more compared to normal diesel. MJD – 1, MJD -2 (Mustard oil 10%, Jatropha biodiesel 10% and Diesel 80%) and MJD – 3 (Mustard oil 20%, Jatropha biodiesel 20% and Diesel 60%) test fuels formed low carbon dioxide emissions compared to diesel fuel 50%, 40.38%and 36.8% respectively . MJD -5-multi blend - test fuel released high carbon monoxide gases compared to diesel of 133.3%. Blend MJD -1 smoke opacity equal to diesel fuel. Blend MJD -2 smoke opacity nearer to the diesel fuel. MJD – 1 and MJD – 2 would be used in diesel engines an alternative fuel for diesel without modifications. Keywords: Performance, emissions, diesel engine, mustered oil, jatropha and diesel multi blended biodiesel.