Numerical Assessment of Energy Efficiency and Sustainability Performance of an Engine Fueled with Bioethanol–Gasoline Blends

The rising need for sustainable energy sources and less dependence on fossil fuels leads to research on alternative fuels. Motorcycles across a wide range of categories often use single-cylinder, spark-ignition, four-stroke engines. This research analyzes the performance of a single-cylinder engine with different bioethanol–gasoline blends at varying engine speeds. The present study used the numerical simulation tool AVL BOOST for one-dimensional simulation. A numerical model was developed for the single-cylinder engine in order to determine its performance, where a number of fuel mixtures were considered at different engine speeds. Parameters such as power, torque, engine efficiency, temperature, BMEP, BSFC, and fuel consumption were obtained to analyze the engine performance. The current results indicate that engines operating on lower ethanol blends achieve maximum power output at lower speeds. The E20 blend produces 12.29% more power and 4% more torque than gasoline. Additionally, E20 demonstrates a 2.89% increase in mechanical efficiency compared to gasoline. The E30 blend performs similarly to E20 and shows potential for reduced fuel consumption at lower speeds, though only E20 exhibits marginal power gains at lower speeds, achieving 52% more power than gasoline. Furthermore, the results highlight that both power and indicated efficiency increase with higher ethanol content in the blends, while the brake mean effective pressure (BMEP) slightly decreases after 2000 RPM. The brake specific fuel consumption (BSFC) ranges from 0.6 to 0.9 kg/kw.h Fuel consumption rises gradually with engine speed; however, after 2000 RPM, fuel consumption using ethanol (E0) increases significantly. Each blend recorded slightly different exhaust gas temperatures. Overall, the findings identify E20 as a promising alternative to pure gasoline for the investigated single-cylinder engine, offering improved power output, torque, and mechanical efficiency. This study provides numerical insights into the influence of ethanol–gasoline blending ratios on motorcycle engine performance and supports the potential use of bio-ethanol blends as a means of improving engine performance and reducing dependence on conventional fossil fuels.