Hydrogen energy is often seen as a key player in transitioning to a sustainable energy future, but recent research is shedding light on the potential of ammonia as a viable alternative in the transportation sector. Ammonia, through a process called ammonia cracking, can serve as a source of hydrogen gas, offering practical advantages over direct hydrogen use. Studies have demonstrated that ammonia can be used effectively in dual-fuel combustion engines, although challenges such as weak flame propagation and combustion kinetics need to be addressed. Researchers have explored the use of ammonium hydroxide emulsion in diesel blends, showcasing increased efficiency and reduced emissions, particularly NOx. The inclusion of water in ammonium hydroxide contributes to lower combustion temperatures, making it a more sustainable choice. Various studies have reported improvements in thermal efficiency and combustion stability when using ammonia and ammonium hydroxide, highlighting their potential in enhancing engine performance while decreasing environmental impact. These findings pave the way for further exploration of ammonia as a sustainable energy carrier in the transportation sector.