The demand for cleaner and more efficient fuels has led to research on alternative additives that can enhance combustion performance while reducing emissions. Diesel-ethanol blends are promising alternatives, but challenges such as phase separation, poor lubricity, and lower energy density limit their widespread adoption. Ionic liquids (ILs) have emerged as effective fuel additives due to their high thermal stability, low volatility, and ability to enhance fuel miscibility. Among them, 1,2-methyl ethyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide (TFSA) ionic liquid has shown potential in improving diesel-ethanol blend performance. Previous studies indicate that ionic liquid additives enhance fuel solubility, ignition characteristics, and emission reduction. Pyrrolidinium-based ILs, especially those with TFSA anions, have demonstrated the ability to improve the stability of ethanol-diesel mixtures. While research on diesel-ethanol blends highlights the need for additives to improve cetane number and reduce knock tendencies, the application of 1,2-methyl ethyl-1-methyl pyrrolidinium TFSA remains underexplored. This study investigates its effects on phase stability, combustion performance, and emissions in diesel-ethanol blends. Experimental results showed that the ionic liquid effectively mitigates phase separation, ensuring homogeneous fuel composition. Ignition delay analysis revealed improved combustion efficiency, likely due to the catalytic effect of the IL. Emission tests indicated a reduction in NOx and particulate matter, demonstrating its potential for cleaner combustion. Additionally, enhanced lubricity contributed to reduced engine wear and increased durability. For future sustainability, research should focus on long-term engine performance, economic feasibility, and environmental impact. Optimizing blend ratios and assessing large-scale commercial viability are essential steps toward integrating IL-based additives into mainstream fuel formulations. This study highlights the potential use of 1,2-methyl ethyl-1-methyl pyrrolidinium TFSA as a promising solution for enhancing diesel-ethanol blends, paving the way for cleaner and more efficient fuel technologies.