Hey guys,

a friend of mine introduced me to the world of HHO fuel cells and ive been doing a bunch of research online and seeing what its all about.

has anyone had any experience or knowledge about these and if theyre legit and worth trying?
My friend has one on his car and said its gets him much further on a tank than normal etc etc but i wanted to see what others thought/experienced.

some places are claiming anywhere between 25% to 130% mpg gains..

so question is, is it worth going the distance to giving it a go?

Haha is this a joke?

No...

If you're talking about those generators that wire in to your car's electrical system and feed HHO gas from separated water into your intake (whether the jam jar type or commercially manufactured), then the short answer is that it is pretty much a scam. The reason is fairly simple - there is no such thing as a perpetual motion machine.

What that means is this: the generator runs off electricity provided by the same engine (or system if you like) that it is feeding more "power" into. The laws of physics state that it is impossible for any system to produce more energy than is used in the operation of that system - otherwise you would have a perpetual motion machine (greater than 100% energy efficiency). So, while there may some fact that the addition of HHO to the fuel/air mixture changes the responsiveness of your engine (entirely possible), the HHO generator *must* still be using more energy than it produces. It total, you're losing more energy with the HHO than without it. Some extensions of this explanation say that if this were not true, you should be able to run the engine entirely off the HHO gas, theoretically. Now if the HHO generator is run by a separate electrical system (2nd) battery, the equation is different, but then you have another battery that you must be charging separately from the cars main electrical system.

I have driven in at least one vehicle with a DIY HHO system, and the change in engine response seems, perhaps, perceptible (placebo effect maybe? who knows). In the end you may end up with more torque or top end power, but you are still losing more energy (total) to power the generator.

Hmmm... you know what? After writing that answer, I'm not entirely convinced that it is the proper explanation. Maybe it's just because I've run out of coffee, but that doesn't seem to make as much sense today as it used to. It seems it doesn't account for certain things. :S

Feel free to debate on that anyone, I'd like to see where this goes...

Hey guys,

a friend of mine introduced me to the world of HHO fuel cells and ive been doing a bunch of research online and seeing what its all about.

has anyone had any experience or knowledge about these and if theyre legit and worth trying?
My friend has one on his car and said its gets him much further on a tank than normal etc etc but i wanted to see what others thought/experienced.

some places are claiming anywhere between 25% to 130% mpg gains..

so question is, is it worth going the distance to giving it a go?

These HHO systems are just updated technology on an old crude system for carby cars. A metal can was added somewhere in the system which had something in it which gave of the hydrogen and boosted fuel economy, they were called 'H-bombs' but experimental.
I wouldn't believe the claims on fuel economy as each system will be different and these systems are still experimental.
You would probably be better off converting to LPG for the money involved.

If you're talking about those generators that wire in to your car's electrical system and feed HHO gas from separated water into your intake (whether the jam jar type or commercially manufactured), then the short answer is that it is pretty much a scam. The reason is fairly simple - there is no such thing as a perpetual motion machine.

What that means is this: the generator runs off electricity provided by the same engine (or system if you like) that it is feeding more "power" into. The laws of physics state that it is impossible for any system to produce more energy than is used in the operation of that system - otherwise you would have a perpetual motion machine (greater than 100% energy efficiency). So, while there may some fact that the addition of HHO to the fuel/air mixture changes the responsiveness of your engine (entirely possible), the HHO generator *must* still be using more energy than it produces. It total, you're losing more energy with the HHO than without it. Some extensions of this explanation say that if this were not true, you should be able to run the engine entirely off the HHO gas, theoretically. Now if the HHO generator is run by a separate electrical system (2nd) battery, the equation is different, but then you have another battery that you must be charging separately from the cars main electrical system.

I have driven in at least one vehicle with a DIY HHO system, and the change in engine response seems, perhaps, perceptible (placebo effect maybe? who knows). In the end you may end up with more torque or top end power, but you are still losing more energy (total) to power the generator.

You are on the right track. The ability of an on board hydrogen-oxygen generator to supply the mix is miniscule, any positive effect is solely in the mind of the driver.
Look at it this way:
Petrol to engine motive power = 20-25% efficient.
Alternator generating electricity = 90 - 95% efficient.
Electricity to hydrogen-oxygen generator = possibly 50% efficient.

ie. energy lost at every step. So where does the "improvement " come from?

Worth giving it a go? Definitely not!

Now an EXTERNAL supply of hydrogen would be different, but there you are just shifting the energy input to power put out by an electricity power generating system, which burns coal, which . . . .

hmm interesting.

i initially thought similarly but after hearing what my friend had to say and claim - yes claim - i decided to dive a bit deeper.

the current draw is less than 20amps, any factory alternator should have no dramas coping with that.
my friends claim is an extra 1/3 mileage per tank since installation (hes had it for about 6 months)

that in my mind, the mileage gain would outweigh the current draw.. in my mind at least. But thats the point of this thread, to see other opinions, experiences, advice etc.

i can definately see where placebo plays it part. but an extra 20% or so in mileage gains is a bit more than mindpower.

im considering getting a kit to trial and see what comes of it.

gain or not, it could be a fun experiment!

i initially thought similarly but after hearing what my friend had to say and claim - yes claim - i decided to dive a bit deeper.

im considering getting a kit to trial and see what comes of it.

gain or not, it could be a fun experiment!

Yep, try it by all means. Your friend is suffering from a syndrome common to crackpot inventions, ie. "I've invested time and money in this, so it must be working." Don't fall into the same trap! lol

Read up on "The Three Laws of Thermodynamics" before you fork out your money though. Especially the on that says energy cannot be created or destroyed. Basically there is no way a 20 amp current can generate the equivalent energy of 1/3 of a tank of petrol.

Yep, try it by all means. Your friend is suffering from a syndrome common to crackpot inventions, ie. "I've invested time and money in this, so it must be working." Don't fall into the same trap! lol

Read up on "The Three Laws of Thermodynamics" before you fork out your money though. Especially the on that says energy cannot be created or destroyed. Basically there is no way a 20 amp current can generate the equivalent energy of 1/3 of a tank of petrol.


are you offering advice or just trolling?

yes energy cant be created nor destroyed, this is supposedly converting the energy. But yes i can see the farfetched claim of amps generating that amount of gain.

Theres a world of info/forums etc about these things so i was hoping to get some local advice, so please keep flaming or junk out of it, im not sold on anything so relax - not specifically aimed at you madmax :) more so to all

Sorry I thought you were referring to a full-on hydrogen powered car.

These HHO fuel cells are an interesting thing, but I can't see how the benefit of the hydrogen outweighs the drain of electricity?

Nope, not trolling nor offering advice. lol I'm convinced the whole setup won't work, based on Scientific principles, but you are free to decide for yourself.

There are hydrogen-oxygen fuel cells in development, but they use hydrogen generated externally to combine with oxygen in a fuel cell to generate electricity to drive the car. The car itself is zero pollution generating, but it takes a lot of electricity to generate the hydrogen, and if that comes from a coal fired power station all you have done is shifted the location of the pollution. Might be useful for inner city transport in large polluted cities one day.

yes, the amount of energy required to 'extract' hydrogen into a consumable state is extremely polluting in itself. Its about as economically viable as a 'Powerband' or 'boost bar' - http://www.aussiemagna.com/forums/showthread.php?t=91427

God forbid anyone with an ounce of humour stumbling across the Tech Torque forum right now lol lol

Do some research - type "hho fuel cells scam" into google and read the reports. Before I retired, I worked for the Bureau of Meteorology - part of the job involved generating hydrogen which was then used to inflate weather balloons. We used a Canadian made electrolyser which punched 400amps @ 12VDC thru 4 large cells filled with a super saturated solution of sodium hydroxide (caustic soda) in de-mineralised water and an anode and cathode. To fill a 100gram balloon (about 1 metre in diameter) took about 1 hour of generation.
The setup suggested for car hydrogen generation uses 20 amps @ 12vdc.......ain't gunna produce much gas!

Please don't get me wrong....I'll always be interested in alternatives.

Since driving isn't a constant load, there may be times (e.g. idling) when the engine still has to run, but isn't moving the car, there could be enough energy that would otherwise be wasted to drive the alternator that bit harder to deliver the extra constant current draw of the HHO cell, and you would use less fuel as the HHO gasses would supply some of that? But in a perfect world, with the engine at the perfect RPM for peak torque/power for maximum fuel efficency constantly, then the extra power drain of running the alternator harder would end up robbing more power than it supplied.

TheCorz - were those H bomb cans a milo tin with some calcium carbide on wet sand to give off acetyline gas plumbed into the intake?

yes, the amount of energy required to 'extract' hydrogen into a consumable state is extremely polluting in itself. Its about as economically viable as a 'Powerband' or 'boost bar' - http://www.aussiemagna.com/forums/showthread.php?t=91427

God forbid anyone with an ounce of humour stumbling across the Tech Torque forum right now lol lol

How true....

those cell are nothing but trouble.... and i have the scars to prove it

those cell are nothing but trouble.... and i have the scars to prove it


Really? Please share!!

in short 2 litre cell, producing ~2000cc/min of h2, 1 small spark, 1 big bang, top of cell flew up in the air hitting the roof (6m above), cathode hit me in the head causing a sizable gash and giving me a concussion, and then the sulphuric acid/water solution rained down on me (fortunately it was only 5% h2so4 but it really killed the eyes), my quick thinking saved my eyes but not my clothes as i immediately ran to the back of the workshop and hosed myself down.

basically they are dangerous, all it takes is a tiny leak below the flame arrestor and a tiny spark and your in deep s##t

in short 2 litre cell, producing ~2000cc/min of h2, 1 small spark, 1 big bang, top of cell flew up in the air hitting the roof (6m above), cathode hit me in the head causing a sizable gash and giving me a concussion, and then the sulphuric acid/water solution rained down on me (fortunately it was only 5% h2so4 but it really killed the eyes), my quick thinking saved my eyes but not my clothes as i immediately ran to the back of the workshop and hosed myself down.

basically they are dangerous, all it takes is a tiny leak below the flame arrestor and a tiny spark and your in deep s##t

Thankyou sir! That is what I was looking for!
Glad to hear your ok. Was there a leak in the hose after the arrestor?

Short of the explosion, did u use the cell during driving and or notice any advantages/disadvantages?

Since driving isn't a constant load, there may be times (e.g. idling) when the engine still has to run, but isn't moving the car, there could be enough energy that would otherwise be wasted to drive the alternator that bit harder to deliver the extra constant current draw of the HHO cell, and you would use less fuel as the HHO gasses would supply some of that? But in a perfect world, with the engine at the perfect RPM for peak torque/power for maximum fuel efficency constantly, then the extra power drain of running the alternator harder would end up robbing more power than it supplied.

TheCorz - were those H bomb cans a milo tin with some calcium carbide on wet sand to give off acetyline gas plumbed into the intake?

Yeah, they were something like that, not sure on the exact details though. Someone I worked with knew of a few old guys 'back in the day' would hook these tin cans up to their cars and they would get more milage and more power.

Those tin cans were probably water injection devices - usually a container full of water with a length of tubing which attached to the vacuum line on the intake manifold - usually you would use the distributor vacuum advance point and put a tee in. You then fitted a clamping device to the tubing so you could control the flow of water which retarded the flame after it ignited...usually one drop a second for a starting point. The perceived advantage was that you could then advance your ignition further than normal without the engine pinking/pinging/detonating/pre-ignition (call it what you like)....anyawy the idea was that it gave you more power. I fitted one to a '69 Transit van with a 1.9litre V4 engine and then a Valiant hemi 265....I thought they gave more power (placebo effect?) but in both cases I chickened out after I heard of instances where the water drained into the engine overnight and in the morning when the car was started it basically locked solid as the piston(s) were full of water - hydraulic lock.
Thinking about it now, I can see why the OP is interested in these HHO gizmos.....so now whilst I think they are a 'scam', I say go for it and good luck.

Thankyou sir! That is what I was looking for!
Glad to hear your ok. Was there a leak in the hose after the arrestor?

Short of the explosion, did u use the cell during driving and or notice any advantages/disadvantages?

i didnt get around to using it on account of my wife (rightfully) banning me from any further experimentation
i think it would have definitely made some sort of improvement... even as an idle substitution system
the leak was between the arrestor and the cell

Point taken!

I have to say thats the first ive heard of water injection, thats very odd indeed.

Thanks all for the input so far, if i end up giving it a crack ill post up and let you all know how i go.

Cheers!

Tim

if you want a lot of the research info its freely available. check out zerofossilfuel channel on youtube. He has a series of 200+ vids on the subject of his own making. Everything he does is open source and he encourages people to take a vested interest how every they can. He also manages to get a closed loop system to run longer on HHOand fuel mix then it did with fuel alone. His premise is that he is not breaking the law of thermal dynamics he is merely making the total system efficiency higher. Which doesnt contrviene the scientific rules we live by but still validates the theory of HHO. His system makes somewhere near 4L/minute at 30A 14.4v DC and that wont even run a 130cc 4 stroke engine on its own but did extend total runtime. Its intersting stuff. The technology exists to have this work its probably just not viable (and by that i mean companies couldnt make money out of it (or enough))

I saw this done on mythbusters the other night interestingly enough...

I'd always been a firm believer in these HHO things being a load of bullcrap due to the small amount of hydrogen they generate.

Now, on mythbusters, they admittedly attempted to run the engine solely on the HHO (which was a 'claim' they were investigating). The car wouldn't even start, so no 'idle' ability in it.
They did not investigate the possible fuel efficiency improvement unfortunately, but they probably should have (they were investigating other fuel saving 'fantasies').

However, one thing that amazed me, was they had a stock carby fed car, and to prove that you 'could' run it on Hydrogen if you wanted, they grabbed a Hydrogen canister, and ran a hose from it over to the 'near' the carby inlet, and then cranked the motor, and 'opened' the canister, and amazingly, the thing started and ran... No special mixers or anything.... Now, I know it is possible to run on hydrogen, but didn't think it would be as easy as just sticking a canister 'near' the inlet and opening it..

SHould've seen the look on Jamies face, when it backfired though.... :P
Descision was possible to do, but not quite safe in the manner they had it setup (and funny to).... But the HHO thing on it's own was baloney...

the mythbusters came to the same conclusion as most people but they really did try half assed. You only have to look at the thousans on youtube who have better attempts them mythbusters (that still dont work )

now while the car ran on straight H from the cylinder it wouldnt have been efficient. Petrol has a small window of useful mixture ratios, where as due to its simple moleucle chain of H (in compressed pure form) it will ignite in any amount of air. so from roughly 4% though too 90% H will run a gasolene engine but obviously there is a good ratio that isnt wasteful and is safe for the engine. HHO (the stuff from the electolysis of water) is a stoichometric mixture as is and the commonly accepted value is around 20L of hho per minutre per litre of engine displacement TO IDLE. To date no one has been able to create this from 12vdc at any amperage (30amp often creates .5 to 3L per minute depending on cell)

id love for this to work and be reality but its a little too soon i think haha though i genuinely believe its been made work somewhere.

http://autospeed.com/cms/title_Diesel-LPG-an-Amazing-Breakthrough/A_110053/article.html
Maybe it would work better on a diesel? Apparently adding a bit of LPG is good for a diesel..

lpg on a deisel has been proven for ages. Basically they use deisel to idle the motor and lpg to idle up the engine. works on light load and requires deisel to keep things lubed up.

Putting things into perspective, most of us have 3 or 3.5L engines. People here are talking about maybe 2L cans of Hydrogen. A 3L engine can inhale 1.5L of air in one revolution. At 3000 R/min, this is 2250 cans of Hydrogen per minute. OK - this is at fullt hrottle, but even at idle, the percentage of Hydrogen getting into the fuel will be minimal.

Putting things into perspective, most of us have 3 or 3.5L engines. People here are talking about maybe 2L cans of Hydrogen. A 3L engine can inhale 1.5L of air in one revolution. At 3000 R/min, this is 2250 cans of Hydrogen per minute. OK - this is at fullt hrottle, but even at idle, the percentage of Hydrogen getting into the fuel will be minimal.

and if you now work out the amount of electrical energy required to generate this amount of hydrogen/oxygen mixture, you will find that it far exceeds the kilowatt output of a car's engine. lol
Hence generating the mix in a car on the move is impossible, and running a car on hydrogen generated externally by a coal powered power station is going to be an expensive and inefficient process.

either process:
car's engine ----> huge alternator ---> electricity to generate hydrogen ---> run the engine

or

coal ---> power station ---> hydrogen ---> car's engine

will be inefficient and expensive.

LPG is a low cost alternative to all this. It exists, it works.

I don't recommend you try this, but one of my sons has a chainsaw that won't start when hot unless he sprays Aerogard into the air intake....works better than Aerostart he reckons.

I don't recommend you try this, but one of my sons has a chainsaw that won't start when hot unless he sprays Aerogard into the air intake....works better than Aerostart he reckons.

lol I had a very tired Victa lawn mower years ago, only way to start it was to wind it over with an electric drill with plug spanner attached, while spraying motorcycle chain lube down its throat. Never failed!

lol I had a very tired Victa lawn mower years ago, only way to start it was to wind it over with an electric drill with plug spanner attached, while spraying motorcycle chain lube down its throat. Never failed!

Great mowers those early Victas - used to call them "toe-cutters".

Great mowers those early Victas - used to call them "toe-cutters".

I like the 2 stroke Victas, pity I can't find parts for them. I have 3 mowers, but only i working carburettor! When that wears out looks like I'm going 4 stroke.

Or I might just tie a bottle of compressed hydrogen to it, and do a Mythbuster "hose down the carby" trick on it. lol

ERAD in simple termsYes you are correct but there is a lot more nitty gritty maths too it.

Or I might just tie a bottle of compressed hydrogen to it, and do a Mythbuster "hose down the carby" trick on it. lol

Just as long as you mix that hydrogen with two stroke oil otherwise it will get pretty dry pretty quickly :P

I was thinking about this a while ago and was even tricked when I started watching videos on perpetual motion. I started reading about thermodynamics and it finally clicked that these guys are insane. It also made me wonder why the hell people are using the alternator to make Hydrogen. Internal combustion engines waste a lot of energy via heat so why not use the heat to generate electricity so you can produce Hydrogen?

Only way to make it work is to take advantage of the wasted energy.

I was thinking about this a while ago and was even tricked when I started watching videos on perpetual motion. I started reading about thermodynamics and it finally clicked that these guys are insane. It also made me wonder why the hell people are using the alternator to make Hydrogen. Internal combustion engines waste a lot of energy via heat so why not use the heat to generate electricity so you can produce Hydrogen?

Only way to make it work is to take advantage of the wasted energy.

aka exhaust driven generator

aka exhaust driven generator

I know, why not set up a compressor/pump driven by the exhaust gasses, that pumps extra oxygen into the combustion chambers?

That'd be a great way to use otherwise wasted exhaust gas energy.

Damn, somebody already invented it - called a turbocharger!

i know, why not set up a compressor/pump driven by the exhaust gasses, that pumps extra oxygen into the combustion chambers?

That'd be a great way to use otherwise wasted exhaust gas energy.

Damn, somebody already invented it - called a turbocharger!

pure gold! Think that's worthy of being a new sig...

What?

I know, why not set up a compressor/pump driven by the exhaust gasses, that pumps extra oxygen into the combustion chambers?
That'd be a great way to use otherwise wasted exhaust gas energy.
Damn, somebody already invented it - called a turbocharger!

Well thats one option, but based on the amount more fuel I use running the air con, I've always wanted to know why you couldn't run the air con compressor off of a turbocharger

I ever said wasted exhaust gas, I meant wasted heat.

All energy transformations eventually end up with heat as a by product and the end product.

If you can work out a way of using the heat produced by a car engine you could make a mint.

Good luck!

I know, why not set up a compressor/pump driven by the exhaust gasses, that pumps extra oxygen into the combustion chambers?

That'd be a great way to use otherwise wasted exhaust gas energy.

Damn, somebody already invented it - called a turbocharger!

Actually its called TIGERS (Turbogenerator Integrated Gas Energy Recovery System)
http://www.cpowert.com/products/tigers.htm

you know that using that TIGERS system would allow people to run very large HHO generators (even though they are usually only 50percent efficient) at no cost to your current fuel usage. That means all Hydrogen production would be "free" compared to a belt driven alternator powered system. By extension then with the use of a tunable ecu im sure someone somewhere could get milage gains from a aystem that requires no extra energy input to create a secondary substitutional fuel source.

Would a hydrogen car produce enough exhaust gas to run a TIGERS system?


Also
I wonder if you could recover the heat from the engine by putting these all over your engine bay :P
This is a type of engine that can use low temperature differences, but it is very weak and practically useless except for looking cool
This one is using the heat from the guys hand

http://www.youtube.com/watch?v=6DBktwPf3rk

You would probably make more electricity using a peltier but those things are still cool.

EDIT: wow that turbo generator is awesome. I had an idea a while ago to do something like that. I called it the turbo gen lol.

PRETZIL no car is going to be able to run off hho, but electricity that is generated at no cost to your fuel consumption, could be used to produce enough while still running the car on petrol to substitute a substantial amount of petrol with hho. in gaseous form i doubt you will make even similar power on hho regardless of how much you can produce but compressed H on the other hand would be very interesting

. . . electricity that is generated at no cost to your fuel consumption, could be used to produce enough while still running the car on petrol to substitute a substantial amount of petrol with hho.


No. Just no.

You are going to create a significant amount of energy in the form of "hho" without input of energy from fuel?

No, just no.

i had built that Water for Gas thing a fair few years back.... worked fine... i dont really want to go into massive detail, but start stop traffic in the city, the car used almost no fuel while idling.... if done right.. they can help with fuel econ... but it was a head **** to maintain constantly and to build everything including control systems..... would rather put a turbo in the car for the same price....

if you re-read properly you will realise i MEAN at no additional cost to your fuel usage (the tigers system isnt belt run, its run from waste heat)

with the tigers system you could run an electrical water pump and PS pump (which is more common on newers cars) thus removing a heap of load from the engine. I gained a lot from an eletrical water pump on my 1.3L swift (6hp peak) and i regualrly see 15km/L where i used to get 13-14/L. i have an underdriven alternator but being able to get rid of it completely and running a tigersof the exhaust gas would be good now that there is a largish draw (especially at low rpm with thermo's running with water pump and headlights).

All energy transformations eventually end up with heat as a by product and the end product.

If you can work out a way of using the heat produced by a car engine you could make a mint.

Good luck!

Like an engine that runs on heat?

http://www.youtube.com/watch?v=LFxNEBhS1AM&feature=relmfu
http://www.youtube.com/watch?v=xF15NA4vR2w
http://www.youtube.com/watch?v=LwrWFb4dcDw&feature=relmfu

Doesn't seem too large a feat of engineering to more efficiently channel the heat produced by an engine and exhaust products to power one of these.

I'm with MadMax...no, no, no. But don't for a minute let those of us that have gone before you and failed deter you....keep searching!

did you even read what i posted? maybe its the wording. I KNOW the alternator cannot give you free electricity, I KNOW that all energy conversion in a car are at a LOSS. What i wa saying is that by removing all the belt driven loads to an engine (TIGERS + Electrical water pump + Electrical PS (more common these days) you could tune your engine to increase economy, even power. Using the waste heat from the exhaust to generate ALL the electrical needs of the car/engine means you woudl then be using NO extra fuel to create the electrical energy the car uses to run the engine and drive. Obviously there is an amount of the fuel the engine will need as a base to run.

Now what i said was, that TIGERS system could be used to create large amounts of hho at no additional cost to your fuel usage BECAUSE ITS DRIVEN by the WASTE HEAT from the exhaust. So the electricity, while still being produced with inefficiencies is FREE when compared to a belt driven alternator, in which case it doesnt matter how much load you put on the TIGERS system, provided it can produce it, it WONT cost you extra fuel over the minimum to run your engine to do so. There is no magic here, its logic. I havent said you can create something for nothing, you can just create something for no additional loss (though its likely that without a belt driven alternator you will gain fuel economy straight off the bat. I did by going to a eletrical water pump instead of belt driven, even though that placed an extra 6amps of load on my alternator, in comparision to a water pump the drag on the crank was less which -= less fuel used. I also have a standalone ecu which allows me to take benefit although the car is setup for peak power not economy)

READ THAT and tell me im still blowing it up my arse.

Lionel

OK. Get an engineer to build this system, do performance tests, then come back and we can discuss cost vs benefits.

This armchair engineering without a practical effort is fairly useless.

Then you all realise the time and effort you went to with this has cost more than the fuel you were trying to save when you started....

i personally havent done anything for the sole purpose of fuel saving, i have done what i have so far to increase power, and with that comes efficiency. This particular system isnt commercially available yet so trying it anytime soon isnt an option. Proof of concept lies in the measurement of peak power and efficiency increases gained from removing belt driven accessories from my engine (this is not a magna btw) Under full load i was able to increase igntion timing and or trim a little fuel (run hotter) whiles accelerating through the rev range at all rpm points due to switching to a electric water pump (davies craig EWP80) even though a load of 6amps was then placed on the alternator. Proof of concpet right there.

If i had the time and money to do a full scale spend on this it woudlnt be to save fuel it would be to reduce emissions. If hydrogen fuelled cars where available now id buy one solely for the emissions benefits, because ultimately hydrogen will be what fuel stations sell in 20years not ULP. You will pay for energy which ever way you go.

How does an axhaust driven generator to make electricity compare to using a smaller engine to reduce fuel use and using an exhaust driven air pump to blow extra air into the intake to make up from the downsizing power loss?

edit: this is possibly a more efficient way of converting heat to energy. http://www.damninteresting.com/the-six-stroke-engine/
intake - compression - combustion - exhaust - inject water, water expansion to steam instead of combustion - steam exhaust - repeat.

I think they did actually make a car with this, but no one ever filled up the water tanks, only petrol, and they cooked.

How does an axhaust driven generator to make electricity compare to using a smaller engine to reduce fuel use and using an exhaust driven air pump to blow extra air into the intake to make up from the downsizing power loss?

.

Fiat do this already with a turbocharger...called Multiair. link: http://seminarprojects.blogspot.com/2011/04/multi-air-system.html