Exhaust and noise emissions of a four-stroke spark ignition engine were investigated by using ethanol-gasoline blends and propanol-gasoline blends. Ethanol and propanol were added to unleaded gasoline at volume percent levels of 4, 8, 12, 16, and 20%. Higher octane number, lower sulphur content, and higher oxygen content were important advantageous of the blend fuels. In general, exhaust emission profile of the engine improved when ethanol and propanol were added into the unleaded gasoline. The CO and HC emissions with ethanol-gasoline blends and propanol-gasoline blends decreased by 65.56 and 33.92%, respectively. NO and CO2 emissions with the blend fuels showed a trend of increasing. In addition, noise emissions with gasoline-ethanol blends decreased slightly at low loads. However, at the other tests, noise levels showed a trend of increasing with the blend fuels.