Review of Performance Testing of Biofuel Blends on a Small Petrol Engine

The depletion of fossil fuels and increasing environmental pollution have accelerated research in renewable energy sources. Biofuels such as ethanol are considered promising alternatives for spark ignition engines. This research investigates the performance and emission characteristics of ethanol–petrol blends (E10, E20, and E30) in a small single-cylinder four-stroke petrol engine. Performance parameters including brake power, brake thermal efficiency, specific fuel consumption, and mechanical efficiency are evaluated under varying load conditions. Emission characteristics such as carbon monoxide, hydrocarbons, carbon dioxide, and nitrogen oxides are also analyzed. Experimental results indicate that low percentage ethanol blends improve combustion efficiency and significantly reduce harmful emissions without requiring engine modification.