Hydrogen as fuel

[totallybonkers]

I'm working in this one myself, if you hear a huge explosion it means I've it got it wrong! From what I've seen of this so far, time to "do it" rather than theorise over it. Over the coming months I plan to duplicate some of these ideas.

One thing I notice is, now everyone Googles things and some tend to believe what their "research" turns up, we now have so many self proclaimed Google Professors.

But that aside, I think there is a another issue. For example if this system works, demand for petrol will drop. Petrol is mostly tax in the UK, so where will the Govt raise tax revenue? UK car tax could go from £150 on my car to £1500 overnight. There will be all sorts of other taxes brought in to replace those lost on petrol.
All I see at the moment is use this tech on a small scale so not to force a change in Govt revenue policy.

[edostar]

The Hydrocarbon Crack System is the easiest way to produce Hydrogen on Demand on your regular car or motorbike.

It's easy and cheap to put an HCS set-up on your vehicle.
Information at: http://www.facebook.com/groups/121433801328438/

I started with a regular HHO booster which crack Hydrogen and Oxygen out of water.
It works but overburdens the engine consuming many of its own gains.

I added an HCS and this worked very well (I even gained some mileage per liter of fuel).

Then I disconnected the HHO and both the power and the fuel savings went up.

Forget HHO.
Fit HCS.

Dan.

[apollo_gnomon]

Hey, edostar. Thanks for mentioning this. A very small amount of googling brought me to a discussion you were involved with on GasSavers forum: http://www.gassavers.org/showthread.php?p=166265

You gave quite a few details in that thread. Might I suggest you start thread here giving an overview for people who may not have heard of this? I think it would be better to discuss hydrocarbon cracking in a separate thread, rather than in an HHO thread.

Thanks! I look forward to discussing this with you.

[edostar]

Hi Apollo_gnomon.

Thanks for the positive response (most people try to prove that it can't possibly work without ever bothering to try it for themselves).

Apart from the GasSavers forum thread; I also contribute to a similar thread on the Fuel Saver forum http://www.fuel-saver.org/Thread-Hyd...racking-System and just set up the HCS facebook page that I gave a link to in my last post.

I realize that HCS isn't HHO but I like to mention it (even at the risk of being slightly off-topic) as it solves the main problem associated with electrolyzing water; the fact that the alternator is running full tilt just to get you some hydrogen.
HCS takes nothing from the engine so any gains in the way of burn efficiency are pure gains.

People tend to like the idea of HHO better because it promises to run your car (at least partly) on water.
HCS cracks hydrogen from regular gasoline vapour which doesn't feel like such a slap in the face to BIG OIL.

If the fuel efficiency gains were marginal; I could sympathize with their lack of enthusiasm but they aren't.
I get around 30% extra mileage running HCS on my fuel-injected Family Car in city driving and the gains are much better out of town.

I agree that a separate thread would be better than interrupting this HHO discussion.
If I start one; I'll link it here.

Dan.

[edostar]

Okay; I just started a new thread to explain and discuss the Hydrocarbon Crack System:
http://www.davidicke.com/forum/showt...post1060915533

I wish the discussion on HHO well.

Dan.

[nongeekywebdude]

Originally Posted by pi3141

Maybe this will help



Consider a 1 litre 2 stroke engine.
Air fuel mixtures for combustion engines should be 14.7% (call it 15% for easier maths)

At 1000rpm there are 500 intake strokes. 2 strokes make 1 revolution.

Thus we need to supply 15% of 500 litres per min

=75 litres per min.

14V HHO cells typically comsume 15 amps to produce 1 litre of fuel per min. 30 amps for 2 litres. (1 cell)

You would need 38 HHO cells all drawing 30 amps and producing 2 litres per min to power a 1 litre 2 stroke at 1000rpm


Consider a 2 litre 4 stroke. (I'm having trouble getting my head around this one but I think the following is correct.)

Each cylinder = 500cc

There is 1 intake stroke in the 4 stroke process

So 1000rpm = 250 intake strokes of 0.5 litres per cylinder

= 125 litres per min

15% of 125 litres = 18.75 litres per minute of fuel, per cylinder

4 Cylinders = 4 x 18.75 = 75 litres per minutre, per 1000 rpm

Again, you would need 38 HHO cells drawing 30 amps and producing 2 litres per cell to fuel the car at 1000rpm
38 HHO cells x 30 amps = 1140

My Lotus redlines at 7000rpm. Therefore to fuel it to max power I would need

7 x 38 HHO cells = 266 HHO cells
7 x 1140 amps = 7980 amps

You can buy batteries with 220aH ratings. You would need 37 batteries to power the system for 1 hour!
Batteries of those capacities weigh 25Kgs = 925Kgs!

I dont get those figures above at all - are you saying a 1 litre 2 stroke engine needs 75 litres per min of fuel and a a 2 litre 4 stroke needs 125 litres per min? Thats 25 gallons of fuel per minute - what sort of engine is that, formula one?

[pi3141]

Originally Posted by nongeekywebdude

I dont get those figures above at all - are you saying a 1 litre 2 stroke engine needs 75 litres per min of fuel and a a 2 litre 4 stroke needs 125 litres per min? Thats 25 gallons of fuel per minute - what sort of engine is that, formula one?

Yeah appologies it got a bit confusing considering gas and atomised liquid petrol. I'm trying to explain how much HHO gas by volume, would be required to run an engine.

I went on to write.

Originally Posted by pi3141

My mistake was the 2 litres of fuel from the fuel pump in my OP. That 2 litres of fuel or 2 litres of LPG is then atomised to represent 15% of the air fuel mixure - petrol and LPG are both stored as liquids. 2 litres of gas from the HHO cell, then mixed into the volume of air passing through the engine would be vastly underpowering the car. If your supplying gas then you need to constantly supply 15% of the volume of air fuel. As it can be seen above - this is way more than 2 litres per min.

My 2.2 litre car has a fuel pump delivery rate of about 2 litres per min of petrol. Thats required at maximum load. That petrol is then atomised to 15% of the air fuel in a 1 Litre cylinder.

Powering a car on HHO would require similar volumes of HHO gas to atomised petrol.

I'm trying to compare 15% volume of HHO gas in 1 litre of air fuel mixture to 2 litres per min of petrol, then atomised. ( I use atomised to describe the carburetion process)

I've also got a 2.6 litre car running on LPG, it has a 90 Litre tank which gives me about 250 miles (Rough guesstimate) The LPG is stored as liquid and then heated before entering the engine.

So how many litres of gas, does 90 litres of LPG make when its heated? Thats how much HHO has to be produced for the engine.

Any help appreciated.

[h2pogo]

Originally Posted by pi3141

Yeah appologies it got a bit confusing considering gas and atomised liquid petrol. I'm trying to explain how much HHO gas by volume, would be required to run an engine.

I went on to write.




My 2.2 litre car has a fuel pump delivery rate of about 2 litres per min of petrol. Thats required at maximum load. That petrol is then atomised to 15% of the air fuel in a 1 Litre cylinder.

Powering a car on HHO would require similar volumes of HHO gas to atomised petrol.

EDIT.. I am guessing the fuel/air ration is much less for HHO..Does any one have any reliable data on this as i hear conflicting figures?

I'm trying to compare 15% volume of HHO gas in 1 litre of air fuel mixture to 2 litres per min of petrol, then atomised. ( I use atomised to describe the carburetion process)

I've also got a 2.6 litre car running on LPG, it has a 90 Litre tank which gives me about 250 miles (Rough guesstimate) The LPG is stored as liquid and then heated before entering the engine.

So how many litres of gas, does 90 litres of LPG make when its heated? Thats how much HHO has to be produced for the engine.

Any help appreciated.

2.2l ideling at 1000 rpm = 2200l/15 = 146.666l Please correct me if i am wrong any one.

I tried a booster on LPG and did detect a slight improvement..Better than petrol.

[nongeekywebdude]

I think the talk of maximum pump ratings and maximum combustion chamber volume is whats causing the confusion. Just because a car engine has a cubic capacity of 2 litres does not mean it uses 2 litres of fuel on every stroke,

if we take the real world example given for LPG

a 2.6 litre car running on LPG, it has a 90 Litre tank which gives me about 250 miles

lets assume hho and lpg have the same calorific value for simplicity (hydrogen is much higher than petrol but dont know about HHO)

A 250 mile journey at a realistic 50mph average means 5hours driving time or 300 mins, this equates to an actual LPG consumption of 0.3 litres per minute (90 litres/300 minutes), rather than the 75 litres per minute quoted before.

So, if I have this right, to completely fuel that 2.6 litre car you would need a gas kit capable of producing at least 0.3 litres per minute

[pi3141]

Originally Posted by h2pogo

2.2l ideling at 1000 rpm = 2200l/15 = 146.666l Please correct me if i am wrong any one.

I tried a booster on LPG and did detect a slight improvement..Better than petrol.

Cheers h2pogo!

I did some checking and found this -

The five-cylinder engine's advantage over a comparable four-cylinder engine is best understood by considering power strokes and their frequency. A four-stroke cycle engine fires its cylinders once every 720 degrees — the crankshaft makes two complete rotations. If we assume an even firing engine, we can divide 720 degrees by the number of cylinders to determine how often a power stroke occurs. For a four-cylinder engine, 720° ÷ 4 = 180° so there is a power stroke every 180 degrees, which is two power strokes per revolution of the crankshaft. A V8 engine gets a power stroke every 90 degrees: 720° ÷ 8 = 90°, which is four power stokes for each revolution of the crankshaft.

http://en.wikipedia.org/wiki/Straight-five_engine

So according to that paragraph there are 2 power strokes per revolution so we should double your figure?

146.66 Litres of gas per minute at 1000rpm - my Lotus redlines at 7000rpm!

[pi3141]

Originally Posted by nongeekywebdude

I think the talk of maximum pump ratings and maximum combustion chamber volume is whats causing the confusion. Just because a car engine has a cubic capacity of 2 litres does not mean it uses 2 litres of fuel on every stroke,

Thats correct, it takes 15% of 1 litre as volume of gas or atomised liquid petrol combined with air.

Originally Posted by nongeekywebdude

lets assume hho and lpg have the same calorific value for simplicity (hydrogen is much higher than petrol but dont know about HHO)

A 250 mile journey at a realistic 50mph average means 5hours driving time or 300 mins, this equates to an actual LPG consumption of 0.3 litres per minute (90 litres/300 minutes), rather than the 75 litres per minute quoted before.

So my LPG system delivers 0.3 litres of liquid petroleum gas to the vapouriser per min, to be heated into a gaseous state which represents 15% of the volume inside the cylinder.

Originally Posted by nongeekywebdude

So, if I have this right, to completely fuel that 2.6 litre car you would need a gas kit capable of producing at least 0.3 litres per minute

HHO gas producers do not produce liquid HHO, they produce gas, so they would need to produce 15% of 1 litre volume of gas per power stroke, if your comparing that 0.3 litre from LPG - LPG begins the process as liquid not gas.

That 0.3 litres per minute liquid LPG then heated and expanded into gas.
How much volume expansion does liquid create when converted to gas?

My petrol fuel pump delivers 2 litres of liquid petrol to the floats per min - that liquid is then atomoised into a mist through the carb and represents 15% of the air fuel mixture in a litre or in my case each 500cc cylinder.

HHO gas generators typically produce 2 to 4 litres of HHO gas per min (I think) - a single HHO bubbler is not sufficient to power a car, a single bubbler will only give an MPG improvement. I spoke to one of the manufacturers and they tell me they are working on building devices to completely power the car - but they are not there yet.

[nongeekywebdude]

Originally Posted by pi3141

Cheers h2pogo!

I did some checking and found this -



So according to that paragraph there are 2 power strokes per revolution so we should double your figure?

No, 2 power strokes from 2 cylinders each revolution, effectively half the engine on each revolution

Originally Posted by pi3141

146.66 Litres of gas per minute at 1000rpm - my Lotus redlines at 7000rpm!

the rpm and cubic capacity of an engine are not the deciding factors in fuel consumption, ignore them, what matters is how much fuel is being injected into the engine. You cant measure fuel consumption by engine cubic capacity nor rpm.

its possible to burn less fuel at a higher rpm for instance, and a 2 litre engine at part throttle can easily return better fuel consumption than a 1.4 litre engine pedal to the metal.

Engine displacement and RPM are an indication of the maximum theoretical fuel consumption only, what matters is actual consumption - see example above

[nongeekywebdude]

Originally Posted by nongeekywebdude View Post
I think the talk of maximum pump ratings and maximum combustion chamber volume is whats causing the confusion. Just because a car engine has a cubic capacity of 2 litres does not mean it uses 2 litres of fuel on every stroke,

Originally Posted by pi3141

Thats correct, it takes 15% of 1 litre as volume of gas or atomised liquid petrol combined with air.

No it does not, if that were true it would not matter how you drove a car,you could measure fuel consumption by rpm only, this is obviously not the case. if your figurs above were correct, a 2litre engine would need 0.15 of a litre every revolution or 450 litres at 3000rpm???

Originally Posted by pi3141

My petrol fuel pump delivers 2 litres of liquid petrol to the floats per min - that liquid is then atomoised into a mist through the carb and represents 15% of the air fuel mixture in a litre or in my case each 500cc cylinder.

No it does not, if that were true, assuming an average fuel tank size of 60 litres, that means you could only ever run your car for a maximum of 30 minutes till you emptied your tank - have you ever driven for more than half an hour?

Originally Posted by pi3141

HHO gas generators typically produce 2 to 4 litres of HHO gas per min (I think) - a single HHO bubbler is not sufficient to power a car, a single bubbler will only give an MPG improvement. I spoke to one of the manufacturers and they tell me they are working on building devices to completely power the car - but they are not there yet.

that may well be true, no idea,

[h2pogo]

Originally Posted by pi3141

Cheers h2pogo!

I did some checking and found this -



So according to that paragraph there are 2 power strokes per revolution so we should double your figure?

146.66 Litres of gas per minute at 1000rpm - my Lotus redlines at 7000rpm!

DOH I just realised We should actually half it..As on a 2.2l four cylinder four stroke each time it fires is just 550cl 2.2l/4
It would take 8 revolutions to suck the full 2.2l of air.

So 70 odd litres..Still a fair bit.

[pi3141]

Originally Posted by nongeekywebdude

I think the talk of maximum pump ratings and maximum combustion chamber volume is whats causing the confusion. Just because a car engine has a cubic capacity of 2 litres does not mean it uses 2 litres of fuel on every stroke,

I know, that would completely fill the cylinder with petrol.
We are talking 1 litre volume of air mixed with 15% litre volume of gas.

In fact in my 2.2l Lotus as has been pointed out, each cylinder, by volume is equal to 0.5 litre. So when the piston goes up and down, it draws in, by volume, 0.5 litre of air of which 15% is HHO gas. Then it compresses it and fires it. But there is little doubt, each cylinder is pumping 0.5 litres volume of air on each stroke of which 15% is HHO gas or LPG Vapour or droplets of petrol from an injector or carb. It is shifting hundreds of litres of air and gas per min.

[pi3141]

Originally Posted by h2pogo

DOH I just realised We should actually half it..As on a 2.2l four cylinder four stroke each time it fires is just 550cl 2.2l/4
It would take 8 revolutions to suck the full 2.2l of air.

So 70 odd litres..Still a fair bit.

Oh yes.

But does your calculation take into account 1 power stroke per rev or 2?

[pi3141]

Here's my LPG system.

Professionally fitted by the company that originally bought the car.

Bay view
Vaporiser bottom right hand corner


Air filter
The big silver feed pipe goes under the airfilter.


LPG Gas ring!
The hose under the airfilter connects to the feeder ring.



They are supposed to stamp the Litres per min, but they don't on the ones I looked at online or on mine - I cleaned it up and checked.

I've checked my vaporiser - it says R90/E and below it G.P.L

This appears to correspond to a max engine power of 139Kw (186Hp)

If they do not specify litres per min then they should say kg per hour, according to section 8 of this paper -

Link - Link - http://www.archsd.gov.hk/english/pub...on_pdf/e24.pdf

I've got a simple Single point - fumigated via a single pipe to the air filter. The advatage of my system, it doesn't take time to warm up, I start the engine, dip the accelerator and switches to lpg before I've pulled away. It works fine except overtaking on inclines or at high motorway speeds.
Quite funny when we first got it - pull out on a car to overtake, kick down, shift gear and watch the car your overtaking pass you by on the inside as you run out of power and slow down behind them.

My LPG system fails at speeds over 90 mph and on the very rare occasion I drive that fast I have to sitch over to Petrol.

[nongeekywebdude]

Originally Posted by pi3141

I know, that would completely fill the cylinder with petrol.
We are talking 1 litre volume of air mixed with 15% litre volume of gas.

In fact in my 2.2l Lotus as has been pointed out, each cylinder, by volume is equal to 0.5 litre. So when the piston goes up and down, it draws in, by volume, 0.5 litre of air of which 15% is HHO gas. Then it compresses it and fires it. But there is little doubt, each cylinder is pumping 0.5 litres volume of air on each stroke of which 15% is HHO gas or LPG Vapour or droplets of petrol from an injector or carb. It is shifting hundreds of litres of air and gas per min.

There is doubt! if your logic is correct both examples below would result in exactly the same fuel consumption as it is the same size engine at the same rpm

a) you are driving your 2.2litre car on a flat road at 3000rpm and barely depressing the accelerator, just cruising along a high speed,

b)you are driving your 2.2litre car up a steep hill at 3000rpm and have your foot almost pressed to the floor to maintain the speed

obviously this is not true, in the second example you would be using much, much more fuel (by several orders of magnitude), even though the engine bore and stroke is the same and the rpm is the same - the amount of fuel injected into the engine is NOT directly proportional to rpm or bore&stroke (cc). The fuel injection system will inject the fuel/air mix required and this will vary tremendously depending on load and throttle use

If your assumptions were correct, there would be no need for fancy computer fuel injection systems, as every stroke gets the same amount of fuel and air anyway, why bother?

[oiram]

Some of my old Free Energy Postings since 2007 ......

http://waronyou.com/forums/index.php?topic=3160.25

Whats about this technology?
http://www.davidicke.com/forum/showthread.php?t=15365



You may have heard about an invention created by a 63-year-old named John Kanzius that claims to create an alternative fuel out of salt water. Through sheer serendipity, Kanzius, a former broadcast engineer, found out something incredible -- under the right conditions, salt water can burn at high temperatures.

Kanzius' journey toward surprise inspiration began with a leukemia diagnosis in 2003. Faced with the prospect of debilitating chemotherapy, he decided he would try to invent a better alternative for destroying cancerous cells. What he came up with is his radio frequency generator (RFG), a machine that generates radio waves and focuses them into a concentrated area. Kanzius used the RFG to heat small metallic particles inserted
http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/salt-water-fuel.htm

Time: x+6 minutes
Voltage:4,8 V
Amp:300 mA
Frequency: 923 cycles per second (Hz)

H/O production achieves maximum with 923Hz.
6. Attempt runs

Time: x+7 minutes
Voltage:4,8 V
Amp:300 mA
Frequency: 1100 cycles per second (Hz)

H/O production becomes smaller with rising frequency. Frequency is gone back gradually on 923Hz.
7. Attempt end

Time: x+9 minutes
Voltage:0 V
Amp:0 mA
Frequency: 0 cycles per second (Hz)

End of the experiment. The frequency was gone back gradually again on 923Hz and held for 32 seconds 923Hz.

X+9 minutes
End of the experiment.
Became by 1.2 litres water
0,5 litres during the experiment split up into hydrogen and oxygen.
http://www.linux-host.org/energy/buerger1.htm

Frequency Keys?? Hydrogen

So - our international-research team- on the- Frequency Keys- to Hydrolysis & Hydrogen- just came up with HOW - the famous KANSIUS ('Can Water Fuel the World!) - got his frequency key to split hydrogen. He took the known sputtering frequency of Palladium (phase conjugate/ PGM!) - 13.56 Mhz. He found out that this radically reduced the power needed to split hydrogen from water. Even the noble Rustum Roy - quickly realized this was the end of Earth's energy crisis. (Check the films and links- water IS power- when you can directly ring out the hydrogen).

I decided to apply the mathematics I had originally discovered to produce the key frequencies I use to make phase conjugate dielectrics. With these frequency recipes- in Phase Conjugate dielectric- materials - I have been able to produce 50% growth increase- measured - in bioactive fields. ( goldenmean.info/phaseconjugatewaterconfidential). The key is to know that the GOLDEN MEAN- and PLANCK TIME CONSTANT (and PLANK LENGTH) define the sacred- and the bioactive - and phase conjugation (and gravity)! I had multiplied the Plank time constant times PHI powers- to get my magic frequency for EVERYTHING. (Take a lesson - you folks who talk about 528 hz - Len Horowitz- and 8 hz etc. being sacred- we KNOW what sacred frequencies are!).

So I took my same original equation- and applied it to Kansius's Palladium / Hydrogen frequency - guess what - I got a perfect multiple of GOLDEN RATIO - to many places of accuracy:

http://www.goldenmean.info/goldenproof/

The Clem Engine.

http://www.free-energy-info.co.uk/Chapt8.html
http://www.davidicke.com/forum/showthread.php?t=15365



The Colman / Seddon-Gilliespie Generator.
This device, patented by Harold Colman and Ronald Seddon-Gillespie on 5th December 1956, is quite remarkable. It is a tiny lightweight device which can produce electricity using a self-powered electromagnet and chemical salts. The working life of the device before needing refurbishment is estimated at some seventy years with an output of about one kilowatt.
http://free-energy-info.co.uk/Chapt3.html


Devices which can provide power at any time, and at any location, include running a standard electrical generator with water as the only fuel (chapter 10). Strictly speaking, the generator runs on energy drawn from the environment and not on water which itself is not a fuel, but as water is fed to the engine, it appears as if the water is a fuel although it actually is not a fuel.

While it is perfectly possible to run this type of generator with water as what appears to be the only fuel, it must be realised that a generator of this type produces noise which will not be acceptable for neighbours if the user lives in a congested city environment. Admittedly, a suitable housing with many carpet-covered baffles would allow good air flow and cooling while reducing the noise to very low levels, but generally speaking, this is a solution for people who like working with internal combustion engines and who live some distance away from other people.
http://www.free-energy-info.com/Chapt16.html
http://www.davidicke.com/forum/showthread.php?t=15365

by Charles Couch
for Pure Energy Systems News
Patrick Kelly, a major documenter of the free energy open source movement, recently reported that three people who live near him had extracted 4 kilowatts of power from a generator (rated for 5.5 kW output) running 100% on 3 liter/minute of hydroxy and cold water fog, using no fossil fuel at all. The system is documented on pages 50-59 of the latest update of the famous Chapter10.pdf document [1.3 Mb] which is pretty much the most referenced beginners guide to hydroxy research.

Diagram from a section titled "Running an Electrical Generator without Fossil Fuel" found on pages 50-59 in the Chapter10.pdf document by Patrick Kelly (who comments below).
http://pesn.com/2009/12/22/9501597_Watercar_electric_generators_on_hydroxy_wa ter/

2004 DODGE PU RUNS ON 100% WATER.mpg


How it Works
For information on how to use the electrolysis process to generate a hydrogen-oxygen gas mixture, and links to companies doing it, see Directory:Brown's Gas.

http://tomhoward.ws/InsiderInformation.htm
For information on how to run vehicles on the H/O gas, running the gas into the air intake, to catalyze more effective burning of the gas or diesel, along with links to companies producing products that implement this approach, see Directory:Fuel Efficiency Hydrogen Injection.
http://www.davidicke.com/forum/showpost.php?p=1060696984&postcount=32

[pi3141]

Originally Posted by nongeekywebdude

There is doubt! if your logic is correct both examples below would result in exactly the same fuel consumption as it is the same size engine at the same rpm

a) you are driving your 2.2litre car on a flat road at 3000rpm and barely depressing the accelerator, just cruising along a high speed,

b)you are driving your 2.2litre car up a steep hill at 3000rpm and have your foot almost pressed to the floor to maintain the speed

obviously this is not true, in the second example you would be using much, much more fuel (by several orders of magnitude), even though the engine bore and stroke is the same and the rpm is the same - the amount of fuel injected into the engine is NOT directly proportional to rpm or bore&stroke (cc). The fuel injection system will inject the fuel/air mix required and this will vary tremendously depending on load and throttle use

If your assumptions were correct, there would be no need for fancy computer fuel injection systems, as every stroke gets the same amount of fuel and air anyway, why bother?

Good point!

I had not considered this.

My Lotus, 2.2l with twin Dellorto carburettor does not have sensors. But as the engine vacum builds, more air is sucked in through other jets, drawing more fuel to contribute to the main jet. Its progressive through the air chambers.

So, quite correctly not only does the volume of air and fuel increase but also fuel for extra load, uphills, with passengers etc.

So to have any hope at plotting how much fuel is required, you need fuel consumption and air volumes at idle and full load, not just high rpm in neutral gear.
Any gas would have to match the fuel volumetrically.

Hydrogen having a higher BTU than petrol and LPG having a lower BTU than petrol, adjustment can be made for the gas volume depending on BTU.
Petrol requires 15% fuel to air mix.
LPG requires more (I get less mpg per litre on LPG than petrol because of this)
Hydrogen would require less.


I still think the best way look at hydrogen powering cars or HHO generators contributing to MPG is to plot this volumetrically to get an idea of how much gas your HHO or Hydrogen generator needs to be making to have an effect on MPG or completely power the car.