In this research work, performance and emissions of Tyre Pyrolysis Oil (TPO) in a diesel engine are experimentally examined as per Indian Standard: 10000. The main objective of this research work is to find the best proportion of blend based on performance and emission analysis. For the study, Tyre Pyrolysis Oil is added to diesel fuel, numbered D100 (pure diesel), D95T5 (by volume of 5% TPO and 95% diesel), D90T10 (by volume of 10% TPO and 90% diesel), D85T15 (by volume of 15% TPO and 85% diesel), D80T20 (by volume of 20% TPO and 80% diesel) and D75T25 (by volume of 25% TPO and 75% diesel). Fuels are tested in four strokes, single cylinder, direct injection, water cooled diesel engine. The effect of various blends on Mechanical Efficiency, Specific Fuel Consumption (SFC) and Thermal Efficiency are investigated by the performance test. The influences of blends on CO, O2, NOx, CO2 and HC are investigated by an emission test using the 5-gas analyzer. The investigation shows that D85T15 blend has been proved best based on performance test compared to other blends. The investigation of Emission analysis shows that D85T15 blend has better combustion characteristics compared to others.