Why Tires Deflate Over Time? Different Reasons and Fixes

Tires are one of the most dynamic and the most important parts of vehicles. And most of the time, you can realize that the tire of your car or your vehicle deflates over time. Here, we will look at the general reasons why tires deflate over time. And you will find very good reasons and how to deal with these problems.

Why Tires Deflate Over Time?

Tires are the systems that we attach to rims and inflate them by applying an air pump. For ordinary passenger vehicles, the pressure of the tire is around 30-35 psi. And it is very important to hold the tire pressure at this value. But, sometimes we see that tires are deflating over time. There are different reasons for it. And if you understand them, dealing with this problem will be much easier for you.

Osmosis or Permeation

Osmosis is one of the most common reasons why tires deflate over time. Also, osmosis means, the ability of atoms and molecules to travel across the tire to get outside. The structure of the tire is not solid to prevent molecules and atoms escape from the tire wall. From the very small holes, the atoms and molecules can escape at very low rates.

In general, a car tire can lose 1-3 psi per month just because of osmosis. And if you leave your car or vehicle for 6 months, this means tires lose air around 6-18 psi. And you can see that the tire is deflated.

So, it is very important to control the tire pressure to be sure that you are at the important range.

Temperature Changes

 Also, temperature changes have a profound effect on tire pressure. Because air can increase or decrease in volume with increasing temperatures or decreasing temperatures.

Every 10 Fahrenheit change, tires lose pressure by around 2%. And in normal climates, the temperature difference between night and day is generally 25-30 degrees Fahrenheit. It is a very big difference that your car tire can lose air by around 10%. Tires do not lose any air. The air inside the tire just shrinks. This means you will lose around 3-4 psi.

So these are the natural reasons why tires deflate over time. To prevent it, you need to check the tire pressure frequently to be sure that you are driving at the right tire pressure.

So the pressure loss of your tires mustn’t be higher than in these natural conditions. If it is higher than these natural conditions and losses, you may have major damage to your wheel.

General Damages on Tires

If you notice why tires deflate over time apart from the natural reasons that we explained above, you need to check for the general damages that happen to your tires. So, it is very important to consider that these tires are not damaged.


You can have a stuck object on your tire that you do not notice. The object can be very small and prevents the escape of air take place in seconds but several days.

It is very important to inspect your car tires with your eyes. Look carefully to see if there is a stuck object on your tire. If it is, you need to apply the important precaustioısn for it.

Damages on Bead

 If there is damage on the bead of the tire, this can be the reason for the air loss of your time over time which is unnatural. So, it is very important to check that there is no damage to your bead.

The damages on the beads generally take place on the old tires. If there are smaller bead damages and there are no specific reasons for these damages, this means it is time to change your tire with a new one.

Hazards from Road

Also, the hazard from the road can cause damage. This means you need to apply it according to prevent any damage to these hazards.

For example, driving a vehicle on a rocky road overly can cause damage or air loss.

Problems with the Valve Stem

From the valve stem you can deflate or inflate your tires. And also the cause of why tires deflate over time can be these valves.

These valves can be damaged and hazards come from the road. And also for old tires, the valve stem can wear out which will lose air over time.

There is a small metal piece that you need to apply a small force on it to open the air inlet to the tire. So, if the stem wears out, an air escape takes place.

This means you need to change the tires with new ones.

Bad Wheels and Rims

The structure and the health of the rim are very important. Because the tire directly sits on the rim. And we inflate the tire on this rim. So, it is very important to inflate the tire with the help of air.

The rim can be corroded or rusted. This means there can be small air escapes that will cause air loss on the rims. So it is very important to check your rims if you are curious about why tires deflate over time.

Also if there is structural damage on the rim such as bents, this can be the reason why tires deflate over time.

How to Prevent Deflating Tires?

If the reason for the air loss from your tires are the unnatural things that we stated above, you can take these precautions;

  • If the bead of the tire is worn out, you need to change the tire with a new one. And also if you need to drive your car on bumpy and rocky roads, select a tire that can withstand these conditions.
  • Check the air pressure of your tires regularly. The recommended time for the air pressure check is generally once a month. Make sure that all the tires of your vehicle are within the 30-35 psi range.
  • If you have a problem with your wheel, you need to bring your car to repair this structural damage on your wheel. And the deflation problem will be solved.
  • If there is damage on the valve stem or if the valve stem is worn out, change the tires with new ones. Do not forget to attach the valve cap every time. It increases the lifespan of the valve stem by protecting it from outside hazards.
  • Change your rear tires and front tires regularly every 6 months. Because the driving force is not the same in each wheel. And if your car is 2 WD from the front tires, this means your front tires will wear out quickly. And changing the rear tires will equate to the situation for each tire.
  • In modern cars, there is a system called TPMS which means Tire Pressure Management System. This is a system that checks the tire pressure every time. And if there is a difference in the tire pressure, there will be a dashboard sign.
  • Also, the optimum tire pressure range is very important for optimum fuel economy. If your tires are deflated, your car will burn more gas.
  • If there is a stuck object on your tire, you can apply tire plugs or tire patches to them. They will solve your problem.

Last Words on Why Tires Deflate Over Time

As you see above, these are the general reasons why tires deflate over time. There are different kinds of reasons for this. And you can take precautions to prevent deflating tires.

If you have comments and questions about this topic, please leave them below.


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Can tires deflate without a leak?

Yes. The tires can deflate without a leak. There are two natural reasons why tires lose air. The first one is osmosis. With osmosis, air atoms ae passing through the minimal passages and holes on the tire wall over time. And also, the temperature range is another important cause of the delating tires.

Why does my tire keep losing air but no hole?

There can be different reasons for it. The osmosis and the temperature changes are natural reasons which you can not prevent. But the worn-out valve stems and very minimal holes can cause this problem. If your car tire loses lots of air in days or several weeks, there is a structural problem with your wheel or your tire.

How do you stop a tire from deflating?

You can not. Osmosis and temperature change are the natural reasons why tires deflate over time. And also you can have structural problems with your tires such as worn out or damaged valve stems, damaged beads, and stuck objects that you need to fix it various ways.


Hello, I am Hasan, I am one of the owners of the Fmechanic. We built this website with one of my best friends to share our knowledge and experience in the engineering and mechanic areas. I am a certified mechanist and I have 4 years of experience with power and manufacturing tools. Writing about these topics and contacting people around these topics is a great joy for me.

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