Influence of ethanol–gasoline blend on performance and emission of four-stroke spark ignition motorcycle

In order to encounter the problems of fossil fuel depletion and global warming, it is very important to search an alternative fuel for transportation sector. Ethanol, one of many alternative fuels, is an attractive source of alternative fuel for combustion engine. Generally, an ethanol is used as blended fuel with gasoline or diesel fuel. In the present work, an effect of blend ratio by volume of ethanol–gasoline fuels (E0, E5, E10, and E15) on performance and emission characteristic of four-stroke motorcycle is investigated experimentally. The work is performed at engine speed of 4000, 5000, 6000, 7000, 8000, and 9000 rpm for each of tested fuels. The result indicates that oxygen presence in the ethanol gives an advantage to combustion process of the ethanol–gasoline blends. The combustion process occurs more completely with the use of the blends. The ethanol–gasoline blend improves the brake power of the motorcycle. The maximum brake power of 6.23 kW is attained with the use of E15 at 8000 rpm. Typically, exhaust gas temperature increases with the use of ethanol–gasoline blends. The highest exhaust gas temperature occurs with the use of E10 at 9000 rpm. The use of ethanol–gasoline blends reduces the brake-specific fuel consumption. The lowest brake-specific fuel consumption of 0.125 kW/kg h is obtained for the use of E10 at 4000 rpm. Meanwhile, CO and HC decline with the use of ethanol–gasoline blends. The lowest CO of 0.11% and HC of 7 ppm are produced with the use of E10 at 8000 rpm. On the other hand, CO₂ increases with the use of ethanol–gasoline blends. The highest CO₂ of 7% is formed with the use of E15 at 8000 rpm.