Effect of Alcohol Blended Fuels on the Emissions and Field Performance of Two-Stroke and Four-Stroke Engine Powered Two Wheelers

Field trials were conducted on two-stroke engine powered two-wheelers with 5%, 10 % ethanol and 3 % methanol. The performance and emissions of vehicles operating on these fuels were compared to those with neat gasoline up to 20,000 km. No significant change in fuel economy was observed with 5 % ethanol and 3 % methanol, however about 1.1 % loss was observed with 10 % ethanol. Emission test conducted after mileage build-up showed reduction of carbon monoxide (CO) with 5 % and 10 % ethanol, while increase of CO was observed with 3% methanol. Total hydrocarbon emissions increased on mileage build-up with all the test fuels. Merit rating of engine components after 20,000 km indicated that the ratings were better for 5 % ethanol blended gasoline. Startability and drivability problems were observed with 3% methanol after completing 10,000 km. A dedicated scooter and four stroke engine powered motorcycle were used for measuring instantaneous toxic emissions and fuel economy with neat gasoline and its blend with 5%, 10% and 20% ethanol. The toxic emission results indicated that there was no significant change in formaldehyde emissions, whereas acetaldehyde increased with all the ethanol blends in two stroke two wheeler. Acetone and Benzaldehyde emissions decreased with all the blended fuels in two stroke two wheelers.

In case of four-stroke engine powered motorcycle, there was no change in formaldehyde emissions, decrease of Crotonaldehyde and Benzaldehyde emissions were observed with different alcohol blends. There was a significant reduction in CO and THC emissions, and enhanced fuel economy was observed with 5% and 10% ethanol blends.