Performance and Exhaust Emissions of a Single-Cylinder Utility Engine Using Ethanol Fuel

The effects of ethanol and gasoline blends on the performance and emissions of a multipurpose 2.5 hp Honda utility engine have been experimentally evaluated. To accomplish this task the engine fuel supply system was slightly modified using off-the-shelf parts. Comprehensive measurements of the performance parameters as well as the regulated emissions (CO, HC and NOx) using gasoline, ethanol-gasoline blends and ethanol were performed. Detailed test results show that significant improvements in performance and emissions can be achieved by using ethanol and ethanol-gasoline blends with high ethanol levels without any apparent adverse effect on the engine for the duration of this experiment. Using ethanol as fuel would improve the power and efficiency by about 30% while regulated emissions could be reduced by 50-60%. In fact, only pure ethanol could easily satisfy future EPA regulation for NOx.