The history of hydrogen engines traces back to World War II when the US engineer Anselm Franz introduced the world's first hydrogen engine, which boasted lower fuel consumption, high power density, and reliability, particularly for aviation purposes. This marked a significant milestone in the development of engines during the war. Fast forward to present times, Achates Power, a California-based company, has revitalized the opposed-piston design by utilizing computer modeling and simulation tools to enhance combustion chamber design and overall performance. Their engines offer up to 30% better fuel efficiency compared to modern diesel engines, with improved reliability and reduced costs due to the design's mechanical simplicity. The company's innovative approach has paved the way for a clean and efficient powertrain technology suitable for transportation applications today. Major automakers like Toyota and BMW are also venturing into hydrogen engines, with Toyota actively testing a hydrogen combustion engine in prototypes like the Mirai. BMW has experimented with a hydrogen-run ethanol engine, envisioning its potential application in larger vehicles such as SUVs and trucks. Moreover, auto parts suppliers like Bosch are contributing to the development of hydrogen components, including injectors and sensors, for integration into future vehicles. Despite the progress in hydrogen engine technology, the article emphasizes the lack of a comprehensive refueling station network as a hindrance to widespread adoption. The article concludes by reflecting on the cyclical nature of history and the urgency to catch up with the futuristic concept of hydrogen engines to revolutionize the mobility sector.