In this work, waste plastic oils were converted into a sustainable alternative fuel utilising the transesterification procedure in the presence of a catalyst and alcohol. In compliance with ASTM, the essential qualities of biodiesel produced were analysed. Fuel mixes like D100 (Diesel fuel), P20D80, P40D60 and P100D0 (plastic oil biodiesel) was obtained. The single-cylinder diesel engine employed in this experiment was completely computerised and used direct injection. With CR18, P20D80 demonstrated a reduction in braking torque of 1.3% and cylinder temperature of 0.7%. At full load, less exhaust gas emissions, including smoke emissions, were recorded. P20D80 mix exhibited more favourable engine characteristics, and P20D80 may be suggested as a possible renewable alternative fuel for conventional diesel when used in engines without modification