We have driven the car about 1500 kms on 250 liters of petrol of petrol, the fuel economy was about 20mpg on highway and about 14mpg around town. The average consumption over the 1500 kms was 16mpg (or 18 liters/100kms).
Whilst we established this record (which we needed to do in order to determine a difference with the post hydrogen installation) we tracked down and ordered a standard hydrogen cell and installed it in the vehicle’s engine bay. We also attempted to track down readymade electronics required to make the cell work efficient (a pulse unit that draws about 2 amps) and eventually bought all the electronic components to assemble it ourselves.
The hydrogen cell installed without the electronics was blowing 30amp fuses and we did not want to draw this much current. No practical solution to limiting the current draw was found. I will go to a TAFE with this problem!
In the mean time we also tried to track down the circuitry required to fool the EFI unit to deal with the excess Oxygen going into the manifold (the Hydrogen Cell produces twice as much oxygen as it does hydrogen!). One solution we had was to space the oxygen sensor away from the exhaust (we have a spacer for this). Doing this would make the car run too lean if no hydrogen is used and the engine may get damaged. An electronic circuit was deemed better which you can switch on or off or regulate in between. This circuitry can be bought via the internet but I was unable to actually obtain it – easier to get Viagra!
As this was happening I searched around for a solution to make a cell which produces no oxygen. This took a few months of experimenting with various components, and I now have one that I believe does exactly that. The oxygen comes out on one end and goes into the air, the hydrogen comes out the other end and is fed straight into the manifold..
The benefit of a small amount of hydrogen in the manifold is that when the spark ignites in the cylinder the hydrogen will immediately explode. This explosion is BEFORE Top Dead Centre which means if it is too big it actually fights against the cylinder which is still moving up. The aim of the small explosion is to fully ignite the petrol mix (coming from the injectors). This has the same effect as buying super duper Titanium sparkplugs and putting a coil on each cylinder. The result is better and more complete petrol combustion, hence more power, and a cleaner emission. Maybe if the electronics of the engine can deal with adjusting engine timing then we can feed more hydrogen in the manifold and go for a bigger cell and maybe gain in power output.
Controlling the current drawn by the cell we can also do by controlling the mix of electrolytic agent in the cell. We tried using vinegar, salt and Caustic Soda. Caustic Soda has a problem in it being caustic and needs careful handling, but it makes for a cleaner running cell (the cell will apparently last much longer and have less built up mineral residues). To maintain a certain concentration of salt (or any of the other electrolytes) is difficult as cells need topping up every 500 kms or so, and trying to regulate voltage with a specific concentration of electrolytes is difficult, hence we like to have an electronically controlled system that allows the cell to draw as much as it is given. This circuit we should be able to adjust to give the cell more or less current, and preferably a pulsed (DC or AC is OK too) voltage.
With the current cell design that only feeds hydrogen into the engine I will experiment in our own car, after I get the current draw issue solved!
The Range Rover is going home without a hydrogen cell installed.
I do not think we will make a huge difference in fuel economy, probably 10-15% at best. The equipment required to do this is not easily available – I was expecting the people in this industry would be more able to deliver!
If I can make the cell work on my own car with reasonable results I will duplicate it for our second car and go from there! I am not sure now how it will work on diesel, but people tell me they have good results in large and small diesel trucks.
So far we have invested just under $1000 in parts and $400 in petrol.