Oxyhydrogen is associated with various exaggerated claims. It is often called "Brown's gas" or "HHO gas", a term popularized by fringe physicist Ruggero Santilli, who claimed that his HHO gas, produced by a special apparatus, is "a new form of water", with new properties, based on his fringe theory of "magnecules".
Many other pseudoscientific claims have been made about oxyhydrogen, like an ability to neutralize radioactive waste, help plants to germinate, and more.
Oxyhydrogen is often mentioned in conjunction with vehicles that claim to use water as a fuel. The most common and decisive counter-argument against producing this gas on board to use as a fuel or fuel additive is that more energy is always needed to split water molecules than is recouped by burning the resulting gas. Additionally, the volume of gas that can be produced for on-demand consumption through electrolysis is very small in comparison to the volume consumed by an internal combustion engine.
An article in Popular Mechanics in 2008 reported that oxyhydrogen does not increase the fuel economy in automobiles.
"Water-fueled" cars should not be confused with hydrogen-fueled cars, where the hydrogen is produced elsewhere and used as fuel or where it is used as fuel enhancement.