This study investigates strategies to enhance the efficiency of Spark Ignition (SI) engine power plants while simultaneously reducing their emissions footprint through alternative fuels, specifically ethanol and compressed natural gas (CNG). As global energy demands continue to rise and environmental concerns intensify, optimizing SI engine performance has become imperative. This research adopts a comprehensive approach that integrates advanced design modifications, fuel optimization, and innovative operational strategies to minimize emissions. Numerical findings demonstrate that implementing enhanced combustion chamber designs and optimized fuel injection systems can lead to a thermal efficiency increase of up to 15%, elevating baseline thermal efficiency from 25% to 40%. The adoption of alternative fuels such as ethanol and CNG significantly reduces greenhouse gas emissions; ethanol blends achieve up to 30% lower CO2 emissions compared to conventional gasoline, decreasing emissions from 2.31 kg CO2 per liter of gasoline to 1.61 kg CO2 per liter of ethanol. In contrast, CNG shows even greater potential for reducing the emissions footprint, with CO2 emissions as low as 0.18 kg CO2 per megajoule, significantly lower than those from traditional fuels. Additionally, the introduction of smart control systems and predictive maintenance strategies results in a 20% reduction in operational downtime, from 15% to 12% of total operational time, contributing to a 10% overall efficiency improvement.