hydrogen cars are total losers economically and energy efficiency:
https://en.wikipedia.org/wiki/Hydrogen_vehicle
“As of 2014, 95% of hydrogen is made from natural gas. It can be produced using renewable sources, but that is an expensive process.[3] Integrated wind-to-hydrogen (power to gas) plants, using electrolysis of water, are exploring technologies to deliver costs low enough, and quantities great enough, to compete with hydrogen production using natural gas.[4] The drawbacks of hydrogen use are high carbon emissions intensity when produced from natural gas, capital cost burden, low energy content per unit volume, production and compression of hydrogen, and the large investment in infrastructure that would be required to fuel vehicles.”
Have you piped it in on top of diesel yet? I have... Using the right plates it works very well from just tap water and a bit of electrolyte.