The emphasis is made on attaining the worldwide aim of looking for alternative fuels to achieve energy security by analyzing the feasibility of technology and evaluating bio diesel and ethanol as promising replacement fuels. An experimental investigation was carried out to better understand the diesel engine performance and emissions characteristics when several fuel combinations such as D100, B20E5, B40E5, and B60E5, were used (where the value represents the proportion of the relevant fuel). Brake thermal efficiency was found to be increased by 2.49% and 3.94% & 5.46% for B20E5, B40E5, and B60E5 blends, respectively. In comparison to diesel fuel, SFC rises by 2.33%, 3.42%, 4.27%, and 5.43% for B20E5, B40E5, and B60E5. Combustion factors enhanced when biodiesel and ethanol concentrations were increased. Among the studied blends, B20E5, B40E5, and B60E5 with ethanol mixed fuel were found to be more promising due to greater combustion and performance and reduced emissions when compared to diesel fuel alone and slight increase in NO<inf>x</inf>. © 2025 Elsevier B.V., All rights reserved.