It is possible to Increase your MPG rating by adding "On-Board Hydrogen Generation",
I DO NOT BELIEVE it is Possible to generate enough Hydrogen to Eliminate Gasoline completely.
At Best, You Might gain a 20% saving.
"However it may cause damage to your motor".

   Click HERE:
A Simple, Cell Construction Method.
In my opinion, This is the Easiest and Cheapest way.

   Click HERE:
A Basic Circuit to "Control Current in a cell".
This is the Easiest and Cheapest way if thats all you need to do.
This circuit was designed as a general purpose PWM device and will remain Available.

These Single and Multiple Mosfet circuit boards
"Are Available" and will remain so.

   Click HERE:
A Simple Circuit to "Control Current in a cell".
This PWM Circuit also controls Frequency.

This circuit board is Available.

   Click HERE:
This is a Revised Circuit for a PDF File, "D17".
It was Designed to Compensate for the 02 Sensor on Newer Cars, But it had ERRORS!
I have Corrected these errors and also designed a PCB for it.

This circuit board "Is Available".

   Click HERE:
This is a circuit for a Mark/Space Generator.
Here is my revised version for this and also a PCB for it.

This circuit board "Is Available".

   Click HERE:
"Schematic of a 3 frequency Generator".
A TL594 Version of "Bob Boyces" Design.
I Haven't personally tested it
But it has been built by others and works as stated.

This circuit board "Is NO Longer Available from me".

   Click HERE, Re: Gasoline Prices, I Suggest you Read This.

A Few words about Generator Construction:

1) The Generator cell must have reasonable surface area on the Plates to generate a reasonable amount of Hydrogen/Oxygen. And a Typical construction would use Stainless Steel for the Electrodes to prevent them from being Quickly eaten away.

2) While a Generator can Generate a reasonable amount of Pressure, I Believe it is more important to release Pressure and generate a Volume of gas. In My Opinion, Keeping hydrogen under pressure in the generator, compresses the bubbles, holding them to the electrodes longer, hindering further production.

DANGER: Hydrogen IS VERY EXPLOSIVE.
So Be Very Careful with How you do all this stuff.

Here are some More of My Opinions::

A)A lot of people have Experimented with this, "Including Professional Scientists with Huge financial Budgets". So far I haven't seen any Documented Results that are even Close to being Practical.

B) Also Some people Claim the Generator must be Resonant to the Frequency,
in order to get successful amounts of hydrogen.

** I have yet to see a Resonant Cell of any kind.

C) Others claim that the Generator is like a Capacitor with the water acting as an Electrolyte. NOTE:) ** A Capacitor uses a Dielectric, Not an Electrolyte.
The Dielectric in a Capacitor MUST BE Non-Conductive.
Normal Water Isn't Non Conductive.

Sorry,) But I Don't Believe Either "B" or "C" statements above.

D) I Do Know that Certain Waveforms in conjuction with certain Generators have been shown to produce Greater Volumes of Gas for a Given amount of Energy. "But Still Far from being Practical Amounts."

E) However, If a Person does achieve this, He or She will come: Unbelieveable Fame and Fortune.

   Click Here, How Much Hydrogen is Needed to Run a Car?
     This is Based on my Truck.

OR Read This "Theory", as given to me by another person:

Assuming a car gets 38 miles to the US Gallon, that is about 10 miles per liter.

One liter of gasoline weighs aproximately .75Kg
The Gasoline / Air Ratio is about 1:14.7.
(1 liter of Gasoline + 14.7 liters of Air)
So the volume of vaporized gasoline will be about 15.7 liters

One Kilogram of gasoline (1.33 Liters) produces about 13 Kwh of energy.
(Or one liter produces about 9.75 Kwh.)
One Kilogram of Hydrogen produces 33.3 Kwh of energy.
So Hydrogen produces (33.3 / 13) 2.56 time more energy than gasoline.

The Hydrogen / Air Ratio is about 1:34.
So the Total volume of this mixture will be about .293 X 34 = 9.96 Liters.
(Error Corrected, Was previously stated as "9.96 Kg".)

Now if this same car above is run on hydrogen and you expect to get the
identical horsepower, it will require .75 Kg / 2.56 = .2929 Kg of hydrogen
every 10 miles.

Next: 0.09 Kg of Hydrogen = 1 cubic meter of Hydrogen Gas or 1,000 liters.

This means that .292 Kg of hydrogen: .292 / 0.09 = 3.2444 Cubic Meters of
hydrogen or 3.2444 X 1000 = 3,244.4 liters of Gas per 10 miles

Assuming a speed of 60 Miles per Hour, or One Mile per minute,
This works out to Needing to generate (3244.4 / 10)
324.4 Liters of Gaseous Hydrogen, "Every Minute".

"This would be Extremely Difficult to acomplish".

************************************************************************

Assuming the car above and 60 Mph and 10 miles per liter.

If one Kg of Gasoline = 13 Kwh of Energy and if one Liter is .75 Kg,
Than 1 Liter will produce about 9.75 Kwh.

Now 9.75 Kwh, that is equivalant to 9.75 X 6 = 58.5 Kw for 10 minutes

One HP = 746 Watts or 0.746 Kw.

Therefore calculating this out:
(58.5 / .746) This car produces a constant 78.4 HP for 10 Minutes.