Does hydrogen on demand really improve gas mileage?

Question

Do those kits really work? The ones where you add water. Electrolysis is used to separate the hydrogen and oxygen.

Answer 1

if they worked don't you think they would be on the shelves of every Sears, Wal Mart and NAPA store in the world?

They are the 21st century version of snake oil. They are a scam.

They also void your engine warranty.

Answer 2

Simply no

The problem with those is that it takes exactly the same amount of energy to make hydrogen as you get when you burn it. The law of conservation of energy is absolute. Plus internal combustion engines only turn about a third of the energy they burn into motion. The rest is lost as heat. So you need a motor that burns 3 times as much fuel as your car to make enough hydrogen to power your car.

Answer 3

The short answer is no!! But like most short answers it leaves a lot out.

If you expect any of them to live up to the expectations and claims you will  be sorely disappointed.

The energy to required to separate water into hydrogen and oxygen is always more than the energy that will be produced in the combustion of the hydrogen.

There is some evidence that there is a small benefit a combustion enhancer reduce emissions. the steam produced in the cylinder does provide some cooling effect and allows higher ignition timing.

All of the benefits will not add up to much but it might reduce emissions.

Do some research by objective reviews such as Wikipedia.

Look up "Water for Gas" or "Warer 4 gas".