Water vapor?

[Hersbird]

So a car has at least 15 or so right? Coolant could get it up to 200 degrees, exhaust should be capable of boiling it without a vacuum applied. If vapor worked, this would make way more vapor, I just don't know how it would help. It would be cool to make your own distilled water with waste heat and vacuum but it would all go into the motor. This would be useful for Mad Max maybe.

[19bonestock88]

A car can make upper teens to low twenties at idle, and nearly 30 under heavy engine braking, but usually much less at cruise...