Chemists, come forth!
My housemate's Dad seems to think he can improve the fuel efficiency of his car using water, that it's the hydrogen from the water, apparently splitting the water molecule using the leftover heat from the engine. I think he is wrong, as it takes more energy to split said molecule than what you will get by burning the leftover hydrogen. This caused an argument by the way. Can you settle this?
(The Luggage is haunted..., Sun 15 Jan 2012, 1:13, 4 replies, latest was 14 years ago)

Nope.
Using heat alone would involve temperatures that would cause the engine to become a pile of glowing liquid. Using electrolysis is no answer either- you'd be converting the chemical energy of the gasoline into electricity, which would then convert the water to hydrogen and oxygen, with huge efficiency losses all along the way.

Tell him to get a smaller car and not speed.
( The Resident Loon Not a demographic. Do not measure., Sun 15 Jan 2012, 1:20, Reply)

Tell him to read this.
en.wikipedia.org/wiki/Fuel_cell

Summary: you can use hydrogen as fuel, but not in the way he's described.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Sun 15 Jan 2012, 1:26, Reply)

"If it was that easy, then at least one of the moto companies would have done it by now"

( G/PP 💩💩💩💩💩&#128, Sun 15 Jan 2012, 7:58, Reply)

To all above, many thanks!

(The Luggage is haunted..., Sun 15 Jan 2012, 12:18, Reply)