Energy and fossil fuel supplies have been threatened by the depletion of fossil fuels on a global scale, as well as by the constant rise in oil prices and the continual increase in environmental degradation. On the other hand, polymer waste has increased due to its usage in a daily lifestyle because of its cheap cost, ease of production, and adaptability. Indirectly, these polymer wastes are causing some major problems for the ecosystem and other living things. By transforming waste polymers into usable energy, can address for both the non-biodegradability of polymers and the need for an alternative fuel. This research paper aims to evaluate the performance of fuel produced by the pyrolysis of polyethylene polymer. Three distinct alcohol additive blends with polymer fuel were investigated in a single-cylinder direct injection diesel engine for their performance and emission characteristics. The engine efficiency of pentanol was found to be about 3.4% higher than that of base diesel, and with 7% better fuel consumption. Additionally, alcohol additives reduced CO emissions by 3.6%–3.8% and HC emissions by 3.5%–3.8%. The results were further analysed using the design of experiment tool, "Full Factorial Design" to determine the most optimal running condition with fuel consumption of 0.4508 kg/kWh, hydrocarbon of 49 ppm and carbon monoxide 0.265% at half load conditions.