Cold start emissions of a motorcycle using ethanol-gasoline blended fuels

The object of this study is to investigate the effect of ethanol-gasoline blends on CO and HC cold start emissions from a four-troke motorcycle. Nowadays, due to catalyst improvements and efficient electronic mixture control, a significant part of the total emissions during a trip takes place during the cold phase. The employ of alternative fuels could be one of means to lessen the cold-start emissions from two-wheeler engines: ethanol is known as potential alcohol alternative fuel for spark ignition engines, which can be blended with gasoline to increase oxygen content and then to decrease CO and HC emissions. From this considerations, an experimental-analytical investigation was performed on the exhaust cold extra emissions of one motorcycle belonging to the Euro-3 legislative category. The study explains a calculation procedure to model the cold start transient behavior of motorcycles in order to evaluate the impact of ethanol addition (10, 20 and 30 vol.%) on cold start emissions compared with a reference commercial gasoline. Results of the tests indicate that CO and HC cold start extra emissions by using ethanol-gasoline blended fuels decrease compared to the use of unleaded gasoline. Emission factors during the cold start transient were quantized as a function of the ethanol percentage in the blended fuels.