**Abstract**

Up-to-the-minute researches of different countries have used conformist seed oils such as jatropha oil, coconut oil for the synthesis of biodiesel. In the present investigation, (pumpkin) *Cucurbita pepo. L* along *Prosopis juliflora* seed oil was used for the synthesis of mixed biodiesel with 5 ml Elaeocarpus Ganitrus (Rudraksha) as additive. Performance tests were conducted using biodiesel blend in water cooled CI engine and the emissions were analyzed using a five-gas analyzer. Pumpkin and Juliflora biodiesels were blended in equal ratio to form mixed biodiesel denoted by PJB. It was observed that there was 51% amplify in Brake Thermal efficiency and 33% diminution in Brake Specific Fuel consumption at the maximum load when compared to diesel for PJB20 blend with 5 ml additive. It was also noted that emission of CO bargain by 75%. CO2 bargain by 16.95%, HC compact by 49.2% and NO compact by 34.2% for PJB20 blend with 5 ml Rudraksha additive than that of diesel. The smoke opacity with respect to diesel was also noted to be concentrated by 6% for PJB20 with additive used as fuel in CI engine without any engine modification.

**Keywords:** *Cucurbita pepo*. L (pumpkin), *Prosopis Juliflora*, B20 biodieseel blend, Elaeocarpus Ganitrus, Rudraksha, Emission characteristics, 5-gas analyzer
