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Can you convert a 1990 4Runner to run on hydrogen?


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Hi there. My good friend who works on cars (not mine tho) told me he’s working on converting his Toyota 4Runner (1990s model) automatic to hydrogen ?? I looked up and unless you have a custom built engine and battery etc., you can’t truly use such a thing for a gas burning auto (SUV in this case).

It looked like Amazon had some “kit” to install that converts water cooling engine water to gas fed into air intake. Sounds real questionable to me. It was listed just under 180.00. Is this a crazy idea? If not why? If it is why? Thanks so much, mark from Upland, CA 

Ps your YouTube is great!! A Long time viewer. Face  

4 Answers

It's been done with some level of success but requires a lot of custom engineering. It's not something that can be accomplished with a plug-and-play kit.



Hydrogen conversions with a piston engine are possible, but they're not plug-and-play $180 things. To truly run on hydrogen, you would need a source of hydrogen, hydrogen isn't available on our planet freely floating, so it needs to be obtained by electrolysis of water (which is extremely inefficient and what your friend is trying to do) or by cracking hydrocarbons at a refinery. The device he's using sounds like some kind of supplementary fuel source, it's not fully running the engine. It's not going to boost range enough to make the investment worth a thing.

To really make a car run on hydrogen, a tank would need to be installed that can take the pressure of liquid or at least compressed hydrogen. Your gas tank cannot take these pressures, not by a long shot. It would need to be more like a propane tank, but much larger. Hydrogen isn't space efficient for its energy content. Most of the external fuel tank on the Space Shuttle was taken up by hydrogen, only the upper third or so was filled with liquid oxygen. Fuel lines, injectors, sensors... tons of things would need to be upgraded.

Everything else engineering-wise that others are saying also applies. It's definitely not feasible on an average Joe salary. 


Those cheap kits on Amazon and eBay don't do anything, they are pretty much a scam. There is a lot more that has to been done to properly set it up and have car run with out issue and to get the most out of it  Spark plugs need to changed to different heat range, head gasket size has be changed in some cases. need a new stand alone ECU or a plug and play Chip , wide band 02. Upgrade  your fuel system.  Then you need to spend hours or longer fully tuning to optimize the system. Even then people who did everything only said they got .5 to 1.25 mpg more. .  There is a lot more that might been needed. I would stay away personally I've seen it installed properly setup and it's a joke. In case you wondering I know 4 people who bought that product 2 if them did everything needed and got rid of it almost immediately.


Your friend is going to be very disappointed from wasting his $180 (even if he doesn't show it). Don't be like him.