This research addresses the environmental challenges posed by engine emissions, specifically carbon dioxide (CO₂), a primary contributor to global warming. The study investigates the performance characteristics of internal combustion (SI) engines fueled by gasoline, compressed natural gas (CNG), and oxy-hydrogen gas (HHO) blends. Experiments are conducted using a Honda 4-stroke, single-cylinder, air-cooled SI engine. A fixed flow rate of HHO at 8 L/min is maintained while varying CNG concentrations from 0.5 to 2.5 L/min in 0.5 L/min increments. The setup includes an electrical loading board with ten 0.5 kW bulbs, managed by an 8 KVA variac to control the load. Engine performance metrics assessed include brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust emission factor, and exhaust gas temperature (EGT). At the optimal blend ratio of 0.5 L/min CNG, the weighted average brake thermal efficiency reached 22.47%, marking a 26.45% improvement compared to the 17.77% efficiency of gasoline alone. By integrating CNG and HHO, this work aligns with sustainability goals, as these cleaner fuels reduce carbon emissions, enhance fuel efficiency, and minimize the environmental impact. The optimized fuel blends demonstrate a strategic approach to achieving greater engine efficiency while supporting global efforts to combat climate change and promote sustainable energy solutions