Since biodiesel is a sustainable and environmentally friendly energy source, using it to replace diesel fuel is one of the most effective methods to reduce CO2 emissions. The experimental work for this project focuses on biodiesel produced from Pangomia Pinnata oil, also known as karanja oil. The physical and chemical properties of Karanja Biodiesel and its blends are examined in relation to petroleum diesel. Additionally, the performance characteristics of diesel engines fuelled with Karanja biodiesel were evaluated using blends of the fuel (KB5, KB10, KB15, KB20, KB25) comprising 5%, 10%, 15%, 20%, and 25% of Karanja biodiesel, respectively. Under a constant load, brake power, brake specific fuel consumption, and brake thermal efficiency were assessed over a range of engine speeds. Response surface approach was also used to calculate the ideal engine operating settings under normal circumstances. An RSM model with three factors, five levels, two blocks, and a central composite design (CCD) foundation was used. The desirability approach-based response surface optimizer of Minitab®16.2.1 statistical software was used to optimise every goal. The proximity parameter set consisting of S (1900 rpm), B (13%), and T (33 N.m.) was determined to be the most effective for engine performance and efficiency