The Korea Institute of Machinery and Materials (KIMM) in collaboration with Hyundai Motor and Kia has developed a groundbreaking 2-liter engine that directly injects ammonia into the combustion chamber at high pressure. This innovative engine addresses challenges associated with gaseous ammonia fuels by ensuring power output stability and reducing harmful emissions through high-pressure liquid injection. By utilizing pure ammonia, the engine achieves remarkable specific output without requiring additional combustion-enhancing devices. The research team improved the engine's performance by optimizing the ignition system, fuel injection timing, and valve operation. A dedicated after-treatment system was also developed to minimize nitrogen oxides and unburnt ammonia emissions, resulting in improved thermal efficiency and power output while reducing harmful emissions. This advancement showcases ammonia as a practical and efficient fuel for various applications, potentially transforming mobility power sources and industrial power generation. Principal researchers highlighted the engine's potential to revolutionize hydrogen transportation and green hydrogen production, positioning ammonia as a new clean fuel-based power solution. The technology not only offers improved efficiency and reduced emissions but also represents a significant step towards sustainable energy solutions in transportation and industrial sectors.