As far as I can tell from the invariably semi-coherent websites that champion junk/scam/conspiracy science like this, "Brown's gas" is what you get when you electrolyse water and don't separate the gases evolved from the cathode and anode. What you get is not a single gas, but a mixture of two gases, H2 and O2, the normal forms of gaseous hydrogen and gaseous oxygen; moreover, the mixture of these two gases will conveniently be perfectly stochiometric. And you couldn't get me to stand anywhere near any sizeable tank of such a mixture, because another name for any container of fully mixed, stochiometric dihydrogen and dioxygen is a fuel-air bomb.

Cooking oil if only a few people do it isn't going to cause major problems but if everyone started to use biofuels we'd be in quite a bit of trouble (this ethanol crap has already caused food price increases), not to mention that you only really save money with cooking oil if you don't pay taxes on your fuel and that if a lot of people start doing it they tend to get fined for tax evasion (has been known to happen).

bestonnet: The people I know who are experimenting with hydrogen injection do not, generally, keep catalytic converters on their cars.

Which is most likely illegal (and for good reason).

bestonnet: The people I know who are experimenting with hydrogen injection do not, generally, keep catalytic converters on their cars.

Lean burn itself can also provide some fuel economy increase but is banned because of a conspiracy, actually because it increases NOx emissions massively compared to a car with a catalytic converter (that requires a roughly stoichiometric mixture to work) and which is quite justified.

Especially since C-SCR doesn't work too well with the sort of model passenger cars are sold on.

Lean burn itself can also provide some fuel economy increase but is banned because of a conspiracy, actually because it increases NOx emissions massively compared to a car with a catalytic converter (that requires a roughly stoichiometric mixture to work) and which is quite justified.

I can see the systems you describe, if finely tuned, producing a small increase in gas mileage. This site is not offering a small increase. It promises to double your gas mileage. You are not going to get a change like that from a minor adjustment in combustion efficiency.

There isn't *much* room for improvement, but that doesn't mean there isn't room for it.

I'm not saying these claims are true, and I'm not saying they're false. What I actually take issue with is the dismissal of claims using simplistic models. Without experimental evidence one way or the other, I would expect to see a detailed characterization of the combustion process demonstrating the inefficacy of hydrogen injection. I have not seen anything close to that. I have seen a bunch of thrashing about with a vague, non-specific model. Its pop science, not a debunking. As a skeptic, I take nearly as much issue with inaccurate pop science as I do with psychics and telekinesis.

The linked site and its relatives in that market (Make your car run faster/better/cheaper with this cheap kit) do seem quite sleazy. People tend to use secondary indicators of legitimacy and competence when they themselves lack the competence to judge a scientific claim. That is what is occurring here, I believe. Whether or not an electrolysis-based hydrogen injection system increases fuel mileage, the sleaziness of the marketing has no impact on the science.

It works, or it doesn't, and arguing with broad applications of thermodynamic principles, when what you really need is a detailed combustion analysis, is pointless.