The long-term durability and reliability of water-powered engines and their components are also important considerations. Electrolysis cells, fuel cells, and hydrogen storage systems need to be robust and capable of withstanding the harsh conditions of automotive use.
https://carsinspections.com/car-interior/revitalizing-your-vehicle-interior-a-guide-to-car-interior-accent-trim/The cost of producing hydrogen through electrolysis, storing it, and using it in a vehicle is currently higher than the cost of using gasoline or other conventional fuels. Reducing the cost of electrolysis technology and hydrogen storage is essential for making water-powered engines economically competitive.