That headline is another example of a viral “life hack” claim. There is no well-established automotive or safety reason that every driver should put a glass of salt in their car.
The claim usually stems from one real property of salt:
- Salt can absorb some moisture from the air under certain conditions.
- Because of this, people sometimes place salt, silica gel, or other desiccants in damp spaces to help reduce humidity.
However, for a car:
What it might help with
- Slightly reducing moisture in a persistently damp vehicle.
- Potentially helping with minor fogging issues if humidity is the main cause.
What it won’t do
- Eliminate significant condensation problems.
- Fix leaking door seals, window seals, or sunroof drains.
- Prevent mold if water is actively entering the vehicle.
- Replace proper ventilation or maintenance.
Downsides
- A glass can tip over while driving.
- Spilled salt can be messy and may contribute to corrosion if it remains in contact with metal surfaces and moisture.
Better solutions for a damp car
- Find and repair water leaks.
- Dry wet carpets and floor mats thoroughly.
- Use the vehicle’s air conditioning and defroster to reduce humidity.
- Consider purpose-made moisture absorbers or desiccant packs designed for vehicles.
So the core idea—“salt can absorb moisture”—has some truth behind it, but the claim that every driver should try it is an exaggeration. If you’re dealing with foggy windows, musty smells, or condensation, it’s usually better to identify the underlying source of moisture rather than relying on a glass of salt.
