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This question on the Skeptics site, entitled "Can an on-the-fly water electrolyzer linked to the air intake improve fuel efficiency of a gasoline engine?" hasn't been answered.

Perhaps it can be answered here, especially since this meta question appears to support that it's on-topic. I still believe it's appropriate to remain on the skeptics site, so perhaps it could be posted here too?

How can I resolve this?

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  • After spending some time with the OP, I have to conclude that this is off-topic for our site. This isn't a question about an actual vehicle with a specific issue or any other topic that fits within the bounds of our FAQ.
    – Bob Cross Mod
    May 1 '12 at 4:18
  • Well, I appreciate your time, and I'm glad that this got resolved in meta. It's frustrating that nobody appears to be able to answer the question though - you'd think somebody out there would have measured their results objectively! May 1 '12 at 4:41
  • @BobCross, it's possibly worth pointing out that though this question doesn't directly relate to maintenance or repair, it is very much fits with this part of the faq's description: "so long as the question is related to engine or engine accessories.", and saying it's off-topic strongly conflicts with answer to the meta question I linked to above regarding vehicle modifications. May 1 '12 at 4:45
  • FWIW it's been answered now...
    – Ben Brocka
    May 18 '12 at 21:23
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From your original question:

Can anyone shed light on whether this research has been pursued and what the results were?

I don't think a research question is appropriate to this site.

However, I can simply answer your question. This won't work:

A car's electrical system (powered by its alternator) is used to power an electrolyzer of water

Electrolysis takes a fair amount of power to create a useful amount of gas. That would require a big alternator. That would increase the load on the engine (and the mass of the system). This would be an exercise in increasing inefficiencies.

Now, if you had a system powered by the consumption of carbon monoxide (i.e., a waste product), that would be more interesting.

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  • It's my guess too that it wouldn't work. However there are smart people who claim it's worked for them - I wonder whether the biggest gain was from simply tuning their engine, rather than from any efficiency gain from extra gases. However, I can't find anyone who has tested it in a way that would give a true comparison of efficiency before and after. Apr 30 '12 at 19:01
  • I will just state that it won't work. The energy required to electrolyze water to the point that you have a useful amount of flamable gas exceeds the amount of energy you're going to get from combusting that gas. This is easily experimentally confirmable.
    – Bob Cross Mod
    Apr 30 '12 at 19:38
  • I agree with the net loss of energy. However, it would also affect the way the gasoline burns inside the engine, which may give an overall efficiency improvement, depending on how well the engine was previously burning the fuel. I'd say that the more efficient the engine was to start with, the less likely that an improvement could be made with the described modifications. This article describes an improvement in fuel economy but be aware the author is not correct about it being a fuel cell: experts-exchange.com/blogs/DrMadAxe/… Apr 30 '12 at 22:31
  • @HighlyIrregular, this whole issue sounds like sophistry to me. If there is a net loss of energy, the whole point is moot. Focusing on some piece of the system to the exclusion of all else is silly. The car is still a car: this will only make it work less well as a transport mechanism.
    – Bob Cross Mod
    May 1 '12 at 2:20
  • When talking about a net loss of energy, I was referring to the burning of the hydrogen and oxygen. If a poorly designed engine that burns gasoline poorly can burn gasoline more effectively with some hydrogen & oxygen added to the mix, then, maybe, there can be a net gain in efficiency in the overall system. As for silliness of focusing on the net loss of energy from combusting the gas that was just electrolyzed (ie a small piece of the system), it was you that did that not me! I'm trying to confirm whether it's possible to have an overall efficiency gain in the complete system. May 1 '12 at 2:40
  • What I'm trying to do is see through all the sophistry spouted about this technology. I'm completely skeptical, which is why I posted the question on the skeptics site. However, I cannot find any scientific evidence that it does or doesn't work. May 1 '12 at 2:44
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    It might be that the only people who have actually tested it are the ones trying to sell it, and they're not going to publish results that prove their products don't work ;)
    – Nick C Mod
    May 2 '12 at 12:10
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    It is fairly easy to prove that it won't work anyway. The chemical reaction of burning petrol is: 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O. Add more H2 and O to the mix and you'll simply end up with more H2O coming out - effectively you're using the energy from the engine to split H2O purely so you can burn it back together!
    – Nick C Mod
    May 2 '12 at 12:14
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    @NickC wins with this comment: "you're using the energy from the engine to split H2O purely so you can burn it back together"
    – Bob Cross Mod
    May 2 '12 at 12:18
  • Would have been better if I had typed "so" correctly though!
    – Nick C Mod
    May 2 '12 at 15:08
  • @NickC, no prob - fixed.
    – Bob Cross Mod
    May 2 '12 at 15:25
  • @NickC, you're starting with the flawed assumption that the fuel is burning completely in the first place. Hence my comment in the question "This seems less likely to be possible in modern cars where more effort has been put into designing an efficient engine." It's all a moot point now, since an answer has been posted (with what I expected as the result). May 30 '12 at 3:59
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Let's set aside the whether or not it's off-topic. Is it constructive? I don't think so. I would vote to close it if it was migrated here for that reason.

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  • Are stating it's not constructive because you don't believe the technology works? Trying to find some evidence as to whether or not that was the case was the whole point of the question! Surely if there was a chance that it could improve efficiency, it would be worth investigating. Anyway, the research suggests the technology is no good, so it hardly matters. May 30 '12 at 3:53
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    From the vote to close options, under "not constructive": "this question will likely solicit opinion, debate, arguments, polling, or extended discussion." Look at the back and forth comments between you and Bob Cross on his answer. Check! May 30 '12 at 4:00
  • Haha, fair point! It was a good question for the skeptics site though, as many of the topics there are contested... May 30 '12 at 4:01
  • I have to concur - I certainly wasn't adding constructive-ness.
    – Bob Cross Mod
    May 30 '12 at 12:09

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