The fossil fuel depletion, harmful emissions, and loss in biodiversity led researches to move toward alternative fuel and fuel up gradation techniques. This study emphasizes on effect of novel Aegle marmelos organic biochar nanoparticles (AMBNs) as an additive to Aegle marmelos (AM) pyrolysis oil blend and their influence on combustion, performance, and emission behavior of diesel engine. The AMBNs are mixed with pyrolysis oil-diesel blend in the concentration of 25 ppm, and 50 ppm by using ultrasonicator. The physicochemical properties of test fuel opuses were studied.Engine analysis was conducted on direct injection, four-stroke, and single-cylinder diesel engine. The experimental investigation was carried out at a constant speed of 1500 rpm and a standard compression ratio of 17.5:1 at varying engine load conditions. The engine behavior of pyrolysis oil-diesel-AMB nano additives opuses was compared with neat diesel (ND). The augmenting AMBNs additive to fuel blend has enhanced the combustion, performance and decreasing the fuel-burning emission.The significances of AMBN50 on engine characteristics was enriched HRR of 53.73 J/deg CA have been obtained, which is 49.41 J/deg CA for neat diesel at peak load. Similarly, higher CP was achieved in AMBN50 of 64.09 bar at CA of 8 after TDC, which is 63.22 bar for diesel fuel at full load condition. The recommended fuel blend AMBN50 exhibits 13.24% of higher BTE, 27.57% lower CO, 19.11% lower HC, 18.46% higher CO 2 emissions as compared with ND. Experimental output responses reveal that new hybrid AMBN50 fuel opus is suggested to attain the suitable engine characteristics for a green and eco-friendly environment.