HHO and why I have been a little bit wrong about it.

For years now I have ranted about how HHO is nonsense, that it cannot possibly save you any fuel, how anyone selling the “technology” is either deluded or a con man (or both).

It turns out that I am a little bit wrong about this, there is a tiny bit of truth to it after all! (However you should still not touch it with a barge pole!)

Dr. Stephen Samuel from Oxford Brookes University in the UK has performed some experiments on “HHO” and SAE published his paper entitled Hydrogen Enriched Diesel Combustion in 2010.

[Musmar and Al-Rousan at the Department of Mechanical Engineering, Mutah, Jordan repeat the experiment here]

I have a copy and have read it but it is copy right of the SAE and so I can’t reproduce it here. Here is a link to where you can buy your own copy.

I have exchanged emails with Dr. Samuel and I have learned a lot. I’m not going to reproduce the entire conversation here, instead I have distilled it down to the important facts about his experiment, what it means, how I was wrong about HHO and why it is still a bogus technology and you should steer well clear of it and anyone selling it. Dr. Samuel has visited this page and read it, he has not chosen to correct me on anything I have written here.


What we know already:

Hydrogen is a flammable gas, it has a lot more energy in it that diesel or petrol, but it is problematic as an alternative fuel as it is difficult to store, expensive to make and when produced by splitting water into hydrogen and oxygen consumes more energy than there is energy in it.

The laws of thermodynamics say that we can’t ever get more energy out of a closed system than we put into it, in fact we can never break even. While running a car on hydrogen is perfectly possible if you are getting the hydrogen from water and the energy to make the hydrogen from the car’s electrical supply then you are going to fail because this would be a perpetual motion machine and they are not allowed.

What I was wrong about:

(the bit HHO proponents will cherry pick and quote me on)

Now Dr. Samuel ran this experiment where he added small amounts of hydrogen from electrolysis into the air intake of a diesel engine and he found that there was a small improvement in engine efficiency, that it burned less diesel. He found that by adding 2.8 litre per minute of the Hydrogen Oxygen mixture that there was a 5.4% reduction in fuel consumption and that this could probably be improved on by adding more hydrogen.

This is partly because the hydrogen is replacing the diesel as a fuel but mainly because the hydrogen is working to enhance the combustion of the diesel.

Additionally one may be able to optimize this by a small amount by optimizing the engine’s timing to take full advantage of the enhanced combustion . Maybe up to 6 or 7%. Not a very big increase in efficiency but certainly not insignificant.

I have always said this is nonsense, it turns out that I was wrong about that. However… on-board hydrogen generation, HHO, is still a nonsense technology that won’t save you any fuel and stronly urge you not to buy into it. Why? Read on.

What I was right about:

(the bit HHO proponents will completely ignore)

Dr. Samuel’s experiment did not use electrical energy coming from the engine to power his electrolysis machine, the energy to split water into hydrogen and oxygen was coming from the mains.

Interesting as it is, Dr. Samuel’s experiment was not to test if on-board hydrogen generators would save any fuel and this is not a valid conclusion to draw from his paper.

It takes a lot of energy to split water into hydrogen and oxygen, had Dr. Samuel’s electrolysis machine been getting its energy to split the water into H and O from the engine then the additional load applied to the engine would probably be greater than any saving made, certainly a lot less than 5.4%.

Increasing the 2.8 liter-per-minute of the hydrogen-oxygen mixture would not help either as the more H and O you make the more load is applied to the engine and therefore the net positive result is still very small, increase H and O production far enough there will be no more combustion enhancement available and therefore the net result will be negative.

How much energy it takes to split water into H and O is very well understood, how much H and O you make is directly related to how much energy is consumed making it, no amount of clever design of electrolysis equipment can get around this.

On-board hydrogen generators will probably burn more fuel that they save, and if you do achieve a positive result it will be very small indeed. So small in fact that is not something you could measure outside of a laboratory in a “on the road ” or “real world” test.

Unless someone finds a way to split water into hydrogen and oxygen that does not consume vasts amounts of energy HHO will not save you any significant amount of fuel.

Anyone that tells you their HHO gadget saves anything more than about 1% has either made a big scientific discovery that no scientist has yet heard about or they are trying to scam you.


  1. Joe Shea:

    April 27, 2011

    Where you’re wrong regarding the Second Law of Thermodynamics in that there is no closed loop. There are two parts to the process, foreclosing a loop: 1) breaking the H20 bonds with electrolysis, which is only 80% efficient. If that was all that was happening, you’dhave a closed loop and a 20% loss of efficency..

    However, there is step 2), in which hydrogen is combined with gasoline, breaking the “loop.”. Ignition of the small hydrogen molecules cause the greatly larger molecules of gasoline to break into smaller molecules that in hydrogen’s presence burn more quickly, efficiently and completely. That is a net positive efficiency. Gasoline typically is only 20% efficient as a fuel (according to ExxonMobil) and if hydrogen raises the efficiency of the burn to just 40%, the net efficiency cost is 0. However, hydrogen typically combusts 80% or more of the fuel. If the efficiency of the fuel burn is raised just to 30%, that is a 50% improvement. When the 20% net efficency loss from electrolysis is subtracted, the overall efficiency gain is 30%. That translates directly into fuel savings, and that is why you would save 30% on gasoline costs.


    Joe Shea
    The American Reporter

  2. Jon:

    Hi Joe,
    I think you have mis read what I wrote – or perhaps I wrote it badly – and I don’t really understand what you are trying to say to me. A closed loop, in this case, is where the energy comes from the diesel fuel alone, that there is no other source of energy. In the experiment carried out at Oxford the loop was not closed since there was another source of energy in addition to the diesel fuel, the hydrogen was being made by a machine not running from the engine, it was getting its energy from an electrical outlet in the wall.
    Additionally gasoline or diesel engines are not 20% efficient (or 40% or whatever) in the sense that 80% of the fuel is unburned, they burn 99.9% of the fuel. The ineficiency comes from some of the energy in the fuel going to heat and sound and not getting to the wheels.

  3. Charles:

    Hi Jon, I read your website with great interest, after speaking to a guy who specialises in ECU optimising for better fuel economy. He mentioned the Hydrogen generator and told me he was in contact with a firm in the Midlands who said they had a “new super efficient generator ” that used less than 1 amp per litre of hydrogen generated.- Naturally I was all ears, and went away with some details of what he had imparted to me.
    I found the companys webpage and noted that they were using “De Verde ” technology fuel cells, so I went to comanies house to get some intel on the companies background.
    Seeems DeVerde Technologies was previously registered as Jubycell, and began trading as De Verde last October.
    When I Googled Jubycell, I came across your site with some more of the names affiliated with John Hickman.

    I have to ask the question as to why the name change of a successful company was deemed neccessary by John Hickman, ?? and why is he not a multi millionare besieged by Motor Manufacturers worldwide wnating to buy this super efficient fuel cell technology from him.

    Also the guy I originally spoke to said the people from the midlands told him that there was an imminent patent on this new technology to protect it, which begs the question – why bother selling something to a network of installers before the patent is lodged, thus protecting the technology, and also if the product is that efficient why didnt he just sit tight and sell it to the highest bidder from within the motor industry once the patent was lodged, making him a multi millionaire overnight .??

    I know the guy who told me this was not trying to sell me anything , it was just a conversation that arose from our mutual interest in fuel saving technology, and he was looking into this as a possible addition to his business, but was by no means convinced, merely curious, as was I.

    I await the patent with interest.
    till then I believe if something sounds too good to be true ….it invariably is !!! Caveat Emptor

  4. Jon:

    HI Charles,

    How much energy it takes to split water into H and O is very well understood, how much H and O you make is directly related to how much energy is consumed making it, no amount of clever design of electrolysis equipment can get around this and anyone who tells you they have a “new super efficient generator” is either mistaken or lying to you.

    And the line “used less than 1 amp per litre of hydrogen generated” is meaningless, Amps are Joules-per-second and a liter is a measurement of volume, it makes as much sense as “a kilogram of seconds”.

    DeVerde Technologies / Jubycell / John Hickman = scam / scam / con man.

  5. Dave Davies:

    You are an absolute idiot
    I note that you have not posted any of my responses to your utter crap; but thast is to be expected from someone who spouts one sided mis-informed nonesense

  6. Jon:

    Hi Dave,
    What does whether or not me being an idiot have to do with anything?
    I have not received any other comments from you, that is why they are not posted.
    In what way am I mis-informed? Please do enlighten me.

  7. Pictsidhe:

    Wow, some strong feelings running here. Time for a bit of proven science?
    Producing hydrogen from electrolysis. One mole of hydrogen gas fills 24.8 litres, this needs 2 faradays of electrical charge to produce, which is 192970 coulombs. 1 coulomb is 1 amp for one second. Assuming an efficient cell can be run at 1.5V you could run 8 from 12V, to produce 1 litre of hydrogen from 8 series cells, you would ‘only’ need 973 coulombs, for 1 litre of HHO, this comes down to a mere 648 coulombs. Maybe it is 1 amp for 11 minutes? stirring in reality I might guess this is actually 1 litre per hour from jam jar tech the HHO people like to use, that would be simple with a single cell running from 12V. It is still sod all compared to Dr Samuels 2.8 litres per minute: 178 litres per hour, for that, try 8 series cells at 21 amps, probably a 1hp load on the alternator, what power was the engine that got a 5.4% effiency boost?

  8. Pictsidhe:

    Dr Samuels used hydrogen, add 50% to his volume to substitute HHO, 267 litres per hour: 31 amps load through 8 series cells

  9. robert:

    People are credulous and like to believe in magic. The whole thing just seems ridiculous starting with the name HHO gas. The people who believe in this “technology” are never going to listen to you as, like conspiracy theorists, any thing that refutes their beliefs is taken as evidence supporting them. About the experiments with the diesel engine, was there a figure for how much less diesel was consumed compared to how much hydrogen was consumed? Is there a change in unburned fuel in the exhaust? Is the combustion occurring at a higher temperature/pressure? There are many changes possible to an internal combustion engine to improve fuel efficiency, two of the big hurdles, (EFI and computer controlled timing,) are now pretty much standard. Ahead lies hybrid electric drives computer controlled valves, regeneration etc. I think the real issue with IC engines is akin to the piston vs turbine engine evolution in aircraft. The last high power piston aircraft engines were real monsters with 28 cylinders and costing millions in todays dollars. The less mechanically complex and much more reliable gas turbine engines had to await the development of technology that could realize them, once this occurred the wasp major and others became obsolete museum pieces. I wonder if battery/fuel cell technological breakthroughs will consign the IC engine with its complex computer controlled variable valve timing, micro turbo charging, hybrid motor assist regime optimization etc etc….to the dustbin where a 40% efficient heat engine probably belongs.

    thanks for providing bent space.

  10. robert:

    that was supposed to read “Thanks for the VENT space”

  11. Z5:

    You forgot to mention the energy gained when recombining hydrogen and oxygen back into water – then steam, and also the amount of energy produced when this is combined with petrol or diesel.

    Your Dr. Samuel only used H, not HHO…. meaning no O, No vapour, No steam expansion.

    Only half an experiment.

  12. Jon:

    You missed the point entirely… this experiment is about supplemental hydrogen enhancing combustion, it is not about HHO. However it is used by some makers of HHO products, not me, to “prove” that HHO does work. And just so you know, air is about 20% Oxygen, so there is plenty of oxygen present. Also supplemental water injection is a real technology too and is nothing whatsoever to do with HHO. Rather than trying to show how HHO may work, why don’t you start at the beginning and show that it does work? Oh, wait, you don’t need to… you already believe it does, no need to actually check…

  13. Jon:

    You can neither gain energy nor produce it, all you can ever do is convert it. Fundememntal physics and 10 y/o can tell you.

  14. Suzan:

    Dear Jon,

    One day scientists like yourself get proven wrong, TODAY is that day.
    visit http://www.universalhydrogen.com

    Unlucky, best get blogging about something else.

  15. Jon:

    Susan, what the hell are you talking about? Where is the proof? This is just the same old nonsense…

  16. Kenneth R Moore:

    Years ago I attended a seminar on engine emission reduction technology and one of the speakers was Professor Harry Watson from the university of Melbourne.

    His team developed an engine that used a reworked cylinder head with a separate pre chamber to ignite a small quantity of hydrogen. This allowed the engine to ignite ultra lean air to fuel ratios which resulted in a 20% reduction in fuel consumption at part load.


    The point is – to achieve this kind of improvement the engine had to have a re designed cylinder head and totally different fueling. And yet some chancers are claiming that they can equal or better these results by using unmodified engines and a plastic lunchbox with an electrode stuck in the top. Unbelievable!

  17. Jon:

    Thanks for that Kenneth,
    You will also note that the H is not produced “on board”, it is from an external source.

  18. Kenneth R Moore:

    Indeed Jon, from memory the Melbourne University cars had a bottle of hydrogen on-board.

  19. JS:

    I work at a company that has been testing all manor of H2 and HHO injection into over the road trucks and stationary gensets. All diesel. As we have gotten better at our measurements and tracking or controlling variables, all efficiency increase disappears. I had an open mind at the beginning but now I am against any claim of better fuel efficiency through trace hydrogen injection.

  20. Mel Bryant:

    Dear WordPress.
    This eco scam site is hugely defamatory to our business and contains incorrect information pertaining to be factual statements. We have tried to ignore it but now the search engine optimisation is such that it is having a damaging effect on business.
    At numerous times, including the web address. it maliciously addresses our family run business as a ‘scam’. We are a genuinely successful and hard working business with lots of satisfied customers (www.hydrogenhybrids.uk.com/testimonials) with a technology that works. Whilst the technology we use is new, it is backed by UK and international patents.
    Despite exhaustively contacting the blogger directly with offers to resolve and test our technology and withdraw the defamatory statements it has fallen on deaf ears. As an aside, the image used on the site is in breech of the copyright holder.
    I would ask for your assistance in resolving the matter and removing the malicious material, designed to cause maximum damage to our business.
    Mel Bryant, Executive Director, de Verde Technologies Limited

  21. Jon:

    Dear “Mel”,
    Contacting WordPress? That is really bizarre.
    Nice revamp of your website… Did you enjoy your little visit from the ASA? They had you remove all the BS from your website and now you have rebuilt it will all the BS removed. Let me guess, if I telephone you will tell me all the lies instead?
    Your business is a scam, the HHO product does not save any fuel. If you had any evidence whatsoever that it did work then you would publish it rather than relying on testimonials from folks that, if they actually exist, are in no way qualified to judge.
    If you want to “go after” someone to get this website shut down then I suggest trying me, this is my site and my server. Oh, but wait, you can’t because everything I say is correct and you can’t prove otherwise… You are a joke.
    See you in court… but I won’t hold my breath because you won’t follow through.

  22. Sam:

    Interesting read. I have seen these HHO kits all over the net and done a little bit of research. I have read that a lot of people do not run pure water but add a certain amount of electrolyte to use less energy in the electrolysis process, in some cases urine is used as urea is supposed to be a good electrolyte. If this technology worked I can only see it working for a couple of reasons. With the addition of “HHO” it should, in theory, speed up the burn of the original air and fuel mixture allowing more of the burn to happen during the ignition stroke and not wasted during the exhaust stroke.

    Secondly, with “HHO” being a very clean burn and the fact it turns back into steam/water after combustion, this could potentially decarbonise the engine and restore some power and economy it had possibly lost.

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