That “put a glass of salt in your car” tip is another viral hack that mixes a small real effect with a lot of exaggeration.
What people claim it does
These posts usually say it will:
- remove humidity from the car
- stop fog on windows
- eliminate bad smells
- prevent mold and rust
What’s actually true
Salt (sodium chloride) is hygroscopic, meaning it can absorb a small amount of moisture from the air. So in theory, an open container of salt can slightly reduce humidity in a very small enclosed space.
But in a real car:
- the effect is very weak
- it works only in limited conditions (low airflow, mild humidity)
- it becomes ineffective quickly once saturated
Why it’s not a reliable solution
- Cars have air leaks and ventilation, so moisture constantly re-enters
- It cannot meaningfully stop window fogging while driving
- It won’t replace proper AC, defogger, or ventilation use
- It can spill and create a mess or corrosion risk if not contained
Better real solutions for car moisture
If humidity or fog is your problem, these work much better:
- Use the car’s AC + defrost mode together
- Fix leaks or wet carpets (common hidden cause)
- Replace cabin air filter if needed
- Use proper silica gel dehumidifier packs (more effective than salt)
- Keep windows slightly ventilated when parked (if safe)
Bottom line
A glass of salt in your car won’t hurt, but it’s not a meaningful fix. It’s more of a minimal, short-term moisture absorber, not a real anti-fog or dehumidification solution.
If you want, I can give you a simple checklist to permanently stop car window fogging in winter or rainy weather.
