The Surprising Reason Drivers Are Keeping Salt in a Glass Inside Their Cars
At first glance, the idea of keeping a simple glass filled with salt inside a car might sound strange, even superstitious. Cars are equipped with advanced climate controls, dehumidifiers, and technology designed to make driving safer and more comfortable. So why would modern drivers resort to something as basic as a household glass of salt? The answer, as surprising as it may be, lies in salt’s natural ability to absorb moisture, neutralize odors, and even improve safety conditions in ways many people don’t expect.
Over the last few years, more and more drivers around the world have started adopting this unusual trick. Social media platforms, DIY lifestyle blogs, and even automotive experts have highlighted how a simple glass of salt, when placed inside a vehicle, can tackle common issues that affect both comfort and maintenance. To fully understand why this works, let’s take a closer look at what salt does inside a car, how it benefits drivers, and whether you should consider trying it yourself.
Salt as a Natural Dehumidifier
The primary reason drivers are putting salt in their cars is moisture control. Cars, by nature, trap humidity. Rainy weather, snow-covered boots, spilled drinks, or even the natural condensation that develops when warm breath meets cold glass can lead to excess moisture in the cabin. Over time, this moisture creates problems—foggy windows, musty odors, mold growth, and even damage to upholstery and electronics.
Salt, however, is hygroscopic, meaning it naturally draws moisture from the surrounding environment. When placed in a glass or container inside a vehicle, it slowly absorbs the dampness in the air. This reduces condensation on windows, making it especially useful during cold, wet seasons when drivers constantly battle fogged-up windshields. Instead of repeatedly wiping the glass or waiting for the car’s defogging system to kick in, drivers who use salt report clearer windows with far less effort.
In fact, this simple trick mirrors what many commercial dehumidifying products do—only it’s much cheaper. A few handfuls of kitchen salt in a small cup can replicate the effect of moisture-absorbing silica packs or expensive car dehumidifier gadgets.
Combatting Odors Naturally
Another hidden benefit of salt in the car is its ability to neutralize unpleasant odors. Moisture and humidity are often the underlying causes of musty or stale smells inside vehicles. By controlling dampness, salt indirectly prevents the growth of mold and bacteria, which are responsible for these odors. But beyond moisture absorption, salt itself has a mild deodorizing effect.
Drivers who eat inside their cars, transport pets, or frequently deal with muddy sports gear or gym bags know that odors can linger long after the source is gone. While air fresheners may mask smells temporarily, salt helps address the root cause by targeting the humidity that allows odors to thrive. Placing a glass of salt under a seat or in a cup holder can therefore keep the interior fresher without relying on artificial scents.
Protecting Car Interiors
Moisture inside a vehicle doesn’t just cause inconvenience—it can actually damage the car. Prolonged humidity can warp leather seats, stain upholstery, and even corrode metal components in hidden areas. Electric systems, including wiring beneath carpets, are also vulnerable to moisture buildup. By absorbing excess humidity, salt helps protect the longevity of a car’s interior and reduces the risk of costly repairs.
Drivers in cold or coastal climates benefit the most from this trick. In northern regions, snow and slush often get tracked into cars during the winter, while coastal areas deal with naturally high humidity levels. In both cases, salt helps create a drier, more stable interior environment, protecting the vehicle from long-term damage.
An Old Trick with Modern Relevance
While the practice may seem like a quirky modern trend, the use of salt as a natural dehumidifier has been around for centuries. Before the availability of modern air conditioning or chemical dehumidifiers, people stored salt in small containers inside closets, pantries, and storage boxes to keep items dry. In some cultures, salt was placed inside homes and even shoes to absorb sweat and odors. Today, drivers are simply adapting this old wisdom to fit the context of their vehicles.
Interestingly, some drivers also place rice inside socks or containers for similar reasons, but salt is often preferred because it’s more effective at absorbing moisture quickly and doesn’t carry a risk of sprouting mold as rice sometimes does.
Safety Benefits: Clearer Windows on the Road
One of the most significant advantages of keeping salt in the car is how it improves driving safety. Foggy windshields are not only annoying but also dangerous, as they reduce visibility and increase the risk of accidents. While most cars are equipped with defogging systems, these take time to work, especially on cold mornings when drivers are often in a hurry.
A glass of salt can help reduce the amount of moisture that causes windows to fog up in the first place. This means drivers spend less time waiting for the windshield to clear and more time focusing on the road. In areas with freezing temperatures, this can be a crucial advantage, especially when driving at night or in heavy traffic.
How to Try It Yourself
If you’re curious about trying this method, it’s simple and inexpensive. All you need is a glass or small bowl and some regular table salt. Fill the container about halfway and place it somewhere stable inside your vehicle—such as a cup holder, under a seat, or in a side pocket. Avoid overfilling, since you want to minimize the risk of spills.
For extra effectiveness, some drivers recommend stirring the salt occasionally to expose more surface area. If you live in a particularly humid region, you may need to replace the salt every few weeks once it becomes damp or clumpy. In dry seasons, the same batch of salt can last much longer.
For those concerned about spills, an alternative method is to place salt inside a breathable pouch or cloth bag, such as an old sock, and tie it shut. This allows the salt to absorb moisture without the risk of loose grains scattering inside your car.
Addressing the Skepticism
Of course, not everyone is convinced by this trick. Some drivers argue that modern cars already come with effective climate controls and that a glass of salt offers minimal improvement. And it’s true that salt cannot replace a malfunctioning air conditioning system or solve major water leaks inside a vehicle. However, for small, everyday issues like mild humidity, foggy windows, or lingering odors, many drivers find that the salt method is an effective, low-cost supplement.
Moreover, in regions where electricity or heating efficiency is a concern, salt offers a passive solution that doesn’t rely on running the engine or burning extra fuel to power the defogger.
More Than Just a Quirk
In the end, the surprising reason drivers are keeping salt in a glass inside their cars comes down to practicality. It’s cheap, safe, easy to use, and surprisingly effective at controlling moisture, eliminating odors, protecting interiors, and even improving safety by reducing window fog. What may seem like an odd or old-fashioned trick is actually grounded in science, drawing on salt’s natural hygroscopic properties and centuries of human experience using it as a preservative and moisture absorber.
So, the next time you notice your car’s windows fogging up or catch a musty smell after a rainy week, you may not need to rush out and buy expensive gadgets or sprays. Instead, you might find the solution already sitting in your kitchen pantry. A humble glass of salt, placed discreetly in your vehicle, could quietly work its magic, keeping your car drier, fresher, and safer—all without fanfare.
