Due to the increasing energy demand and environmental pollution, with spark-ignition engines, ethanol, methanol, natural gas, hydrogen and alternative fuels such as LPG is used. Alcohols produced by biomass sources has an important place in alternative fuels because of theig heigh octane number. In this study effects of the unleaded gasoline and fusel oil blends in a spark ignition egine on engine performance and exhaust emissions examined experimentally. Tests were performed at full load conditions with four-stroke, single cylinder, fuel injection type spark ignition engine. The ignition time was set to maximum engine torque position. Experiments were performed at different engine speeds with fusel oil and gasoline blends. It was observed that, the highest increase on engine torque was obtained as % 3.4 for F30 blend. Specific fuel consumption of all engine speeds increased depending on the amount of fusel oil in the mixture. The highest increase in specific fuel consumption and 7.7% were obtained in F30. Nitrogen oxide (NOx) emissions decreased depending on the amount of oil blends Fusel, hydrocarbon (HC) and carbon monoxide (CO) emissions have increased.