This is what I have seen over the past four months, sorry not good, in fact so bad I quit, after a lost/cost of around $25,000.00.
I have worked on about 12 cars and only one had a unknown defect.
The rest all were fine good running cars.
Many got good mileage at first but all have problems show up, some with in a couple of days.
Three saw no improvement.
We got mileage in two cars (32 to 43MPG) and got 71 MPG and 81 MPG up from 32 MPG stock on two other cars, and took two vans from 12 MPG to 19/20MPG, BUT not one would not hold it, all faded away with in a few days to a week and all got problems, like stuck idle motors (2), boiling water and gunk in the motors,(4) two got plugged air filters, one HAFC blew apart and sprayed chemical all over the engine.
One van is a 87 MiniVan and has no computer to fight us but it loses it mileage with in a week and we have to clean and renew its water and chemicals.
Now I sure you will say I do not know what I am doing, perhaps, I was trained by one of their best trainers and certified as a trainer myself, and IF I did not know what I was doing how did I get such high mileage's figures??
I quit the company when I saw all of the last cars: two vans and four cars and the problems we were getting, I for one can not afford to buy someone a new motor after this system eats the motor.
I have been warning everyone I could with this email:
I will repeat this warning as often as needed.
There are two main risks: explosion and chemical damage to your engine.
Beware of any that call for lots of chemical, (KOH, NaOH (lye)) use double bubblers to help catch any before going to your motor. It does not stay in the tanks but can get into your motor as gas, I will post pictures of a Bubblier that contains this gunk and how it coats the walls to show you of this problem.
http://www.racprops.com/HAFC/Crud in Bubblier/
Feed gas below your air filter to let it be you last line of defense.
DO NOT use any of the wire and glass jar units.
What every unit you get if they do not tell you to control the main relay with the Fuel Pump relay, be worried what else they did not tell you correctly.
NEVER NEVER set it up to turn on any other way BUT so it comes on after the motor is running and is turned off automatically with the motor.
I know of three cases where this was NOT done, one burst his air cleaner, another broke his intake manifold and the third one was lucky his battery was dead that morning as his ran as long as the battery was able to power it, one spark and good by truck.
Many cells start making gas within seconds and it can fill the air cleaner before you get started, add a slight misfire and BOOM.
NEVER NEVER hook it up to any engine vacuum.
The Fuel pump relay is the way to go.
IF there is no fuel pump relay (like Toyota) use the oil presser sender.
I feel this is so important I will give the design away.
http://www.racprops.com/Hydro Fuel Cell/
Rich