This is another viral “life hack” headline, and it’s mostly exaggerated.
What it’s claiming
Putting a glass of salt in your car is often said to:
- remove moisture
- stop fog on windows
- prevent bad smells
- keep the interior “dry”
The science behind it
Salt can absorb a small amount of moisture from the air (it’s hygroscopic). So in a very small, sealed space, it can reduce humidity slightly.
Why it doesn’t really work in a car
A car interior:
- is not airtight (air constantly enters/leaves)
- has frequent temperature changes (which create condensation)
- produces more moisture than a small cup of salt can handle
So in real-world use:
- the effect is very weak
- it won’t meaningfully stop fogging
- it won’t solve dampness problems
Possible downsides
- spilled salt can damage upholstery or electronics over time
- it can become damp and clumpy
- it does nothing for the actual cause of fog (temperature + humidity difference)
What actually works better
If the goal is fog or moisture control:
- use AC + defog setting together
- fix leaks or wet carpets
- use silica gel or proper car dehumidifier packs
- ventilate the car when safe
Bottom line
A glass of salt in the car is a social media hack with minimal real effect, not a reliable solution.
If you want, I can give you a few proven, cheap ways to stop car windows fogging permanently.
