As far as I know it's not DOT approved.
The sellers
claim that this will not effect your warrantee, however they recommend (at least from what I've read on one site) removing everything and going back to a factory configuration before taking it into the dealership for warrantee service. They also recommend setting it up in such a way that when you go back to stock config, there's no evidence that the HHO system was installed.
This leads me to believe that this will void your warrantee. Of course every dealership is a bit different, for example I know people who have a 3" lift and wheel hard (breaking stuff) that's been fixed under warrantee, while another dealership will tell you that any lift will void the warrantee.
Go into your local dealership and ask, but I'm willing to bet what they're going to say....
You: "Yes, I'm highly modifying my engine by leaning it out a huge amount, modifying a whole bunch of signals that the ECU receives, and dumping an unknown quantity of hydrogen into the intake. If I blow up my engine, is this covered by warrantee?"
Dealership:
From my research there are
VERY conflicting claims on what the hydrogen does.
I've read everything from "your engine doesn't even burn it" to "it's the special sauce that makes it all work".
Here's what I know about it:
Hydrogen ignights at a higher temp than gas, which (if you had enough hydrogen) might lead to some sort of two stage combustion, which would fit with the claims of "extending the burn time".
Hydrogen burns faster and hotter than gasoline, which conflicts with the "slows the burn down" and claims I've seen of "making your engine run cooler." Now, you are dumping some water vapor down the engine, so those claims may come from that...
All that being said, I don't believe there's enough hydrogen being produced (even at max capacity) to make a large difference. Additionally since it's completely unmetered, there's no way of evenly distributing the hydrogen over all 6 cylinders.
As for the first, I believe that the cells produce so little hydrogen due to the inherent risks of it. First, if you produced too much, you start intoducing problems like backfires and such (look at the Mythbusters video clip on YouTube when they dumped hydrogen into a car). Secondly, since hydrogen burns much hotter than gas, you run the risk of physically damaging the engine very rapidly (think of melting aluminum hot).
As for the second, it's expensive and requires fairly extensive modifications to meter and evenly distribute the hydrogen. Plus there's no way of covering it up by removing it, unlike the setup now. Look at the propane kits that folks are using, and you can see an example of a
working and
proven setup. But even with that setup there are risks and dangers....the difference is the claims being made and the acknowledgement of the risks. It's all up front--unlike the HAFC stuff, which has some silly claims out there (100+ MPG from a 20 MPG vehicle), TONS of conflicting information, and claims zero risk.