The present investigation discusses the evaluating diesel engine fueled by Low Density Plastic Pyrolysis Oil (LDPPO) made using a fast semi-batch catalytic pyrolysis employing Zeolite as a catalyst at a temperature of 550°C. Experiments involving the mixing of diesel fuel were carried out on a diesel engine, limited to single cylinder and LDPPO performance analysis- diesel blends in varying proportions like 10%, 20%, 30%, 40%, and 50% in volume proportions. The Brake Thermal Efficiency (BTE) has been noted to be closer to diesel, and the Brake Specific Fuel Consumption (BSFC) was lower for the 30% LDPPO mix than diesel and higher for other LDPPO mixtures. Carbon Monoxide (CO), Hydro Carbon (HC) and smoke were noted to be lower, and the Nitrogen Oxides (NO) were diminished for the LDPPO30 mix at peak load operations as similar towards the diesel. The analysis of Cylinder pressure and the study of Heat Release Rate (HRR) is more significant than diesel up to 30% LDPPO fuel mixture. According to the test findings, the 30% LDPPO-diesel combination is suitable for replacing diesel fuel without requiring any modifications. © 2023 Elsevier B.V., All rights reserved.