To answer your second question first: no it won’t work.

These systems are nothing but a cruel scam designed to con people out of their hard-earned cash.

Yes, you’ll find plenty of people (some who will no doubt post answers here) that claim "it works, I’m saving ..% after fitting it to my car. Go to http://www…. for more information"

But they are invariably lying.

Why are they lying?

Because these scams work by recruiting affiliates who are effectively paid to lie about the system. When they tell these lies and convince people to visit those sites, they earn up to $50 for each sale that’s made. My investigations have revealed that virtually none of the people who join these affiliate schemes and promote these hoaxes save any fuel — and that’s because they don’t even have devices fitte to their own vehicles – they’re only in it for the money.

But if you want to find out more about the scam and why the claims made for these "water powered car" systems are bogus, visit the site I’ve linked to below.

And as to your first question: you can not build an HHO generator because there is no such thing as HHO gas.

When you perform electrolysis on water (regardless of whether you use straight DC or pulsed DC), all that you get is a mix of H2 and O2. This mythical HHO gas they’re talking about simpy dos not exist because unless they’re in a plasma (ultra-high temperature), hydrogen atoms immediately bond to form a hydrogen molecule (H2).

So there is *no* magic HHO gas, just a mixture of hydrogen (H2) and oxygen (O2) molecules in a 2:1 ratio. What’s more, since only a tiny amount of this gas can be generated using the avaiable electrical energy your car’s alternator can deliver, it does *nothing* to improve your fuel efficiency and in fact will *reduce* the efficiency.

Now just sit back and watch the scammers try to tell you otherwise and refer you to their websites so they can make some money out of you.

Please tell your friends and family about this scam so they don’t get conned too.
References :
http://aardvark.co.nz/hho.shtml

Mine works…check out this website.

http://www.myspace.com/trinityenergies
go to their pics and the diagram to build one is under the dialex 100a section. there are 5 pictures there.

After reading the first response above I would like to say that I am in no way, shape, form, or fashion associated with trinity energies. They were just helpful and the ones that told me where to look on their site to build one. I requested to buy one from them just so we could see it before we built our own. Lots of people are skeptical…we were too. We paid a grand total of $102 (includes shipping and insurance) to get it here. Basically we figured we’d blown more on dinner out before so if it didn’t work, so be it. We went in with a very open mind and were prepared to be let down but we weren’t. I’m not going to make any money by referring you to their website. Also, my HHO generator is in my vehicle. If you live near TN you are welcome to come by and see it for yourself.

I will caution you that it is NOT maintenance free so just be prepared to spend about 10 minutes a week under your hood. Nothing major…just changing out your electrolyte mixture and water and making sure your electrodes are clean.

Do your own research. I got mine from them and drive a 2001 chevy suburban 2×4. I am currently getting 28 mpg. I got my first from them and then my husband built one for our 4-runner. We had never dealt with anything like this before so we wanted to see what we were getting ourselves into before we built one ourselves.

Yes there are scams out there but this one does work very well. Oh, and my suburban is fuel injected so yes, it will work on your Jetta.

Make sure your Jetta isn’t still under warranty. It will most likely void it if it is.

If you do want to build one, you are free to e-mail me to find out where to get some the parts. You can get them all at hardware stores and auto parts stores but there was one part that was in a weird section at Lowes. It cost us a grand total of $30 to make our own.
Hope I gave you some insight.
References :

Thank you for your help!