Author Options:

Why don't superchargers and turbochargers break the laws of physics and HHO generators do? Answered

I saw an article today on how HHO generators are just a scam.  There are of course many scams associated with it, but I have yet to test the whole thing myself so I have yet to form a solid opinion on the whole thing.  One of the biggest arguments is that based on the laws of thermodynamics, the same energy is required to split the water as is released when they recombine.  This is true, but couldn't there be other benefits to the whole thing which are being ignored.  If that statement was true wouldn't eco-boost engines be a scam.  The turbocharger can't just create energy can it.  The exhaust which spins up the turbo causes back pressure on the engine right. Then there are friction and slip as well.  It seems very lossy right, but it works. It isn't a scam.  The same goes for a supercharger, the same energy of the added compressed air is taken from the engines drive train.  Now I understand that the compressed air causes a better burn similar to mixing KNO3 with sugar vs just burning it in plain air.  But what if you mix gunpowder and sugar, why is that any different.  I feel like this analogy accurately displays what is going on in both cases, and I feel like there could be an argument for the benefits of HHO. Again I have no experience in the subject yet, but it all seems reasonable. The HHO isn't being used as a fuel, it is being used as a booster which pulls more energy, more efficiently from the petrol.


The forums are retiring in 2021 and are now closed for new topics and comments.

Best Answer 6 years ago

1. There is no such thing as an HHO generator. The devices described generate hydrogen (H2) and oxygen (O2).

2. Claims that the gases they produce are in some way special are wrong.

3. Claims that the gases burn to produce more energy than was used to generate them are wrong.

In short, so called "HHO generators" break no laws of physics, but some people, through ignorance, carelessness or outright deception claim they do.

However, it is potentially possible that the addition of hydrogen and oxygen could improve the efficiency of a petrol-fuelled engine.

Unfortunately, devices tested with scientific rigour either break-even, or reduce the engine efficiency. It appears that anecdotal reports of dramatic efficiency improvements are due to claimants unconciously driving mire carefully after installing the devices.


5 years ago

1. turbochargers do not create "back pressure" against the engine exhaust. The turbine side makes use of the hot expanding gas in the exhaust. the Tailpipe section after the turbine is ususally 2-3 times the diameter of the exhaust pipe that enters the turbine from the engine.

2. as the hot gas expands through the turbine (p x dV), it flows over the turbine vanes, causing lift, just like a series of little wings. this causes the turbine wheel to turn, creating work.

3. work is transmitted from the turbine side to the compressor side via a common shaft.

4. the compressor side converts some of the shaft work into compressing air (p x -dV).

5. due to friction in the bearings, frictional losses in both the turbine and compressor and heat conducted through the housings, some energy is lost (called entropy).

Similarly, Diesel engines rely on High compression in the cylinders and Low pressure in the exhaust pipe (you'll see they are bigger than gas engines) to achieve higher efficiency.

Jack A Lopez
Jack A Lopez

6 years ago

The legend I have heard is hydrogen can serve as an accelerant


for to help the charge of petrol burn more completely.

However there are a couple of caveats. One is you have to start with an engine that is not burning its fuel completely. E.g. if your engine is already burning 90 percent of its fuel, leaving 10 percent unburned, then there's only that much possible room for improvement.

Another caveat is the hydrogen has to make up a significant fraction of the fuel mixture. Numbers I have read/heard are typically in the range of 5 to 10 percent hydrogen by enthalpy, by heating value.

For example, this page,


says that HCNG is "4–9 percent hydrogen by energy", and this mixture, of hydrogen and compressed natural gas, burns better than plain compressed natural gas (CNG) without hydrogen.

I think the first place I heard the legend of hydrogen boosting, was a video sold here:


From an audio excerpt (mp3) of this same video I found here,


at about 9min+15s, I hear the number, "5 - 7 percent of the BTUs", for the hydrogen fraction.


6 years ago

Turbo chargers and Superchargers work by making the internal combustion engine more efficient.

The size of the explosion in the cylinder is related to the amount of fuel you put in. However that fuel needs to be mixed with the correct amount of air to burn efficiently.

So just more fuel is the whole answer. To get more air into the engine you need to re-design the air intake system, at some point making it bigger isn't the answer and the turbo comes into it's own. The turbo uses exhaust gasses to spin a fan to force more air into the engine, combined with more fuel this gives you more power.

The supercharger uses the engine power (usually mechanically connected) to force a fuel air mix into the engine under pressure. Thus giving more power.

They work because the basic internal combustion engine isn't very efficient in the first place.

HHO however is a different matter. The biggest problem with using it to power and engine is the sheer volume of gas you need to feed the engine. As yet no way has been found to economically crack water into Hydrogen and Oxygen fast enough despite various claims.