Experimental Study on the Effects of Biofuels on Performance and Emissions of a Motorcycle Engine

The effects of bioethanol fuels on the engine performance and emissions of the Suzuki GSX-S150 motorcycle were investigated in this study. Four fuel samples, including RON 95, E5, E5′, and E10′, were used for testing the engine at throttle valve openings of 5%, 10%, and 15%. The results show an increase in engine power over the ethanol volume percentage in the fuel. At lower throttle positions, fuel consumption tends to decrease when using ethanol-blended fuel, particularly at lower engine speeds, although this difference diminishes as engine speed increases. Conversely, at larger throttle positions, ethanol-blended fuel shows an initial increase in fuel consumption at low engine speeds, but at high speeds, it exhibits lower values. Furthermore, the Japanese cycle testing indicates that RON 95 provides the lowest fuel consumption, followed by E5, E5′, and E10′. In terms of emissions, biofuels lead to increased CO and HC emissions; NOx emissions increase with the ethanol percentage at low speeds in all three throttle positions, while at high speeds, ethanol-blended fuel produces lower NOx emissions. Notably, CO2 emissions show distinct characteristics, in which E10′ yields the lowest emissions across all throttle positions and speed ranges, while E5 and E5′ exhibit higher CO2 emissions compared to RON 95.