In this study, thermodynamic and economic analyses of binary fuel blends (E15, EA15, M15, MA15, and T15) using commercial gasoline as fuel and oxygenated fuel additives (ethanol, ethyl acetate, methanol, methyl acetate, and terpineol) at 15% by volume in a spark-ignition engine were performed. Performance and emission tests were carried out at various engine loads at a constant speed of 1500 rpm using commercial gasoline and five different fuel blends. Thermodynamic analyses were carried out on the test data. The augmentation in engine load caused an increase in exergy losses and a decrease in the unit cost of engine power exergy values. Specifically for gasoline fuel, the unit cost of engine power exergy at 25% engine load is 1.99 times higher than at 100% load. In fuel blends, the pump price of each fuel affects the fuel cost rate. Exergy efficiency in fuel blends increases with increasing engine load. The highest exergy efficiency is 19.58% for gasoline fuel at 100% engine load. It is 15.95% for M15 fuel at the same load. The exergy values of G100 and T15 fuel were closest to each other and T15 offered better energetic and exergetic performance than the other binary blends.