It's real. My neighbor used to buy junkyard motors, and convert to run on nothing by Brown's gas. No gasoline at all. It is quite possible, but it's a pretty in depth conversion. It can be done on the cheap, but maintenance costs are ridiculous. If you do it right, you're look at over $10k to convert a small 4 cylinder, but the maintenance is much lower. It doesn't have the volatility of hydrogen, but it still has the explosive power of it. It truly is a super fuel, but it far more expensive to use then it is to purchase. IIRC, it only works with distilled water, and it uses a LOT of it. Double MPGs on a 30 MPG car, would be 60 MPG. Assuming you use one gallon of fuel, and one gallon of water, that 60 mpg cost you ~$4 ($3 for gas, $1 for the water), as compared to $6. You need special injectors, a water rail, special plugs, a different t-stat, and several other things to do it right. I helped him to it to an Acura 3.2 V6. This guy also powered his house with solar panels, dirt, and potatoes. And he had a pirate radio station that had like a 4 block radius...