I read this article. It confirmed my thoughts that the H2 generator mentioned here is not only innefective but dangerous.
Please read this. The guy knows what he is talking about.
I apologize if this curbs your enthusiasm, but it is a good reality check as it shows the math and hard fact involved with running hydrogen.
Those E Bay sellers are hosing people.
The E Bay generators make around 3 liters of uncompressed gas per minute(under Ideal conditions). Your van needs 700-825 liters per minute to run at 60 mph. Even adding the 3 liters per minute would not provide enough offset in fuel supply to give the results you are saying it provides.3 liters isnt even 1% of the engines fuel requirement. I doubt it would give any increase in mileage whatsoever.