The Truth! Do Tires Lose Air When Not Driven?

Ever wondered that when you park your car for a few hours or days, the tire pressure decreases, and you can end up driving with an almost flat tire.

This is a reality, and there are multiple factors why this whole issue develops.

So, this article will reveal to you different reasons as to why you suffer from a lack of air in your tire.

The Science Behind Losing Air in Tires

So, what is the science behind your car losing air in its tires? This is a significant issue for some people who like to travel a lot and have to leave their car at home for some days.

Weight is one factor that is very dominant in a tire losing air over time. Over a certain period, your car weight begins to increase due to the action of gravity. 

The continuous gravitational acceleration would increase, and this will increase the pressure on the tires. 

This pressure renders the tires lose air through the air intake valves that have clearance for increased tire pressure. 

These air valves are necessary for regulating tension in the tire, which is an opening where the air pressure continues to decrease.

When you notice your car tire flat, you would certainly think it might be because of a leakage or someone may have punctured your time. 

Well, to be honest, sometimes that is the case, but at times, it is just gravity doing its natural thing. 

It’s not necessary that a leak is the only way by which a car tire can lose air pressure

It can also be due to the irregular maintenance sessions of the tire. Unequal weight distribution on the wheels is also a significant reason why the tires can lose air pressure. 

Take a look at the internet; you will know that gas molecules are always very far apart from each other and have a lot of capacity to be compressed. 

Due to this compression, the air in tires keeps on compressing and goes out through the control valves

So, this is majorly the science behind tires losing air over time.

Valve Stems: An Outlet for Air in Tires

Valve stems are the components of the tire through which the air pressure is maintained. 

It is self-regulatory and seizes the air inside the tire to prevent any leakage or air discharge. 

This also serves as the inlet for the air when refilling. If your tire isn’t punctured, then there are significant chances that the tire pressure is falling because of a fault valve stem. 

Upon parking your car, make sure you check the valve stem if it isn’t leaking. 

Apply soapy water to it, and you will notice bubbles which would indicate whether the tire is losing pressure or not. 

What if you checked the valve stem and the tires of your vehicle still lost air pressure? 

This is a common problem. 

Irregular weight distribution on the tires can put excessive pressure on the valve stems, which eventually results in failure.

Wheel Damage: A Reason for Tire Pressure Loss

If you are an active user of your car on rough terrains or your daily commute is filled with bumps and sharp turns, you would constantly need to get your wheels checked. 

At times, the rims of the tires can be damaged, and you may not even know about it. 

Damaged wheels would again put irregular pressure on your tires that can cause permanent deformation of the rubber. 

This consistent pressure on the tires results in leakage of air through the edges of the rims. 

The bead of the tires is probably the most affected part, and you may need to replace the tires altogether once they are damaged.

Here are a few types of common issues you might see in your tires

Hole in Tire Sidewall

Another reason why your car tire can lose air pressure when standing still is also because of a hole in the sidewall of the tire. 

There are four parts of a tire: crown, shoulder, sidewall, and bead. Three out of four of these parts are non-repairable, and if they are damaged, you would simply need to change your whole tire altogether.

The sidewall is one of the most sensitive parts of the tire, and there are high chances that a nail or sharp corner may have damaged the sidewall during cornering. 

A hole in the sidewall is quite a rare incident, but this can happen, especially if you are running through a rocky pathway. 

While running, the tire may not deflate as fast as when standing still because the weight is equally distributed consistently over the tire’s circumference. 

So to give you a heads up, make sure your sidewall is always in the best condition to avoid any major collapse of the tire.

Nail in the Tire

One of the most common reasons why car tires deflate is because of a nail being stuck in the crown of the tire. 

Usually, it is difficult to pull out a nail, and in some cases, the nail does not come out that easily, and the wrong mechanic would advise you to continue using the tire even though the nail is still there. 

This is the part where you make a major mistake because the nail continues to lose air when the car is sitting idle.

Little-by-Little the air keeps on leaking, and eventually, you end up noticing that your car tire has lost a significant amount of air.

Hole in Thread

Threads are the part of the tire where most of the contact is absorbed by the car during transit. It is significant because it provides traction and control to the vehicle, and most of the wear and tear is felt on this part. 

A hole in the thread can, however, result in significant issues for you, and even a tiny hole won’t be problematic during running, but once the car is still, air would continue to leak. 

This would eventually result in a flat tire, and you wouldn’t even know about it.

Corroded Wheel and Tire Damages

Corrosion is a universal problem, and in the case of tires as well, corrosion can cause significant problems for a car owner. 

If your car does not have an alloy rim, then you would face a lot of issues of wheel corrosion that can impact the sustainability or health of the tire too. 

Corroded wheels result in overall deformation of the wheel, which can cause an imbalance in the air pressure distribution. 

This imbalance would result in pressure differences across the circumference, add to that the weight of the car, and that would result in your tire losing air over time.

Bad Repair Job

You often come across different types of mechanics, and it is not always true that mechanics can provide better repair facilities. 

A bad repair job of any part of the vehicle would cause long-term problems, and similar cases can be seen in the case of tires. 

The tire repair job is by far the most crucial factor that needs to be taken into close consideration when going for a long break from the car. 

So, if you come across a puncture or damage to the wheel, then make sure you go to the right mechanic so that a proper repair job can be done to your tire. 

If the mechanic does improper repair work, there are higher chances that the air in your tire may leak while standing still.

Missing Valve Cap

Ignoring the importance of a valve cap is a common mistake that people often make. 

People consider valve caps as just an additional accessory. Instead, it serves a very beneficial purpose to the air pressure in the tire. 

If you leave your car still for an extended period of time and you don’t have the valve cap on, then it’s evident that your tire will lose air over time. 

As mentioned earlier, valve stems regulate air pressure, and there are chances that the car’s weight on the tire might cause the valve stems to leak. 

To prevent these leaks, valve caps are utilized, and once you apply a valve cap onto your valve stem, it can save you from a lot of hassle later on.

The Effect of Parking Style

Another factor that is responsible for air loss in the tire is the parking style which can be improper at times. 

If you parked your car on an uneven platform, the tire would lose air faster than the rest of the tires under more pressure. 

The same concept of unequal weight distribution is applicable in this case too!

Final Thoughts

So, in conclusion, you must take the necessary steps before you park your car for a more extended period to prevent air loss from the tires. 

There is no guarantee that the tires will never lose air, but it can save you from a lot of hassle and prevent permanent damage to car tires which would save you a lot of costs too. 

Soapy water can be a good indicator that can show you if you need to add air or if a new valve is needed. 

Making sure that the bead area is not impacted is essential. That prevents the hassle of replacing tires damaged due to low pressure.


Dean Alvarez, TireForge Head Author

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