How To Tell if a Tire Is Flat or Just Needs Air: Quick Guide

Learning how to tell if a tire is flat or just needs air is essential, especially for beginner drivers and car owners. Your tire most likely leaks if you observe one of these signs: tire sidewall is significantly flat, only one tire is flat, it’s the exact tire over and over, or the frequency of refilling is unusually high.

Tire Is Flat or Just Needs Air

Our team will take you through these and other symptoms below, including identifying a leak or puncture on your tire, so read until the end!

How To Differentiate Between Leaky and Naturally Flat Tires?

To differentiate between leaky and naturally flat tires, be aware of a leaking tire’s symptoms. A flat tire with a significantly flat sidewall primarily indicates a puncture (leak). Other signs that your tire has lost pressure due to a leak include going flat overnight or abnormally low PSI.

A flat tire is one that needs air. You can experience a flat tire due to a puncture, leak, or through changes in the weather (atmospheric pressure). In the latter situation, all you would require is to add air to your tires. Many vehicle drivers have found themselves in a situation where they start their vehicle in the morning and are greeted with a “Low Tire Pressure” warning. Alternatively, you might glance at the wheels and see that one or all are flat!

When your tire is deflated, it doesn’t always mean that it has a puncture. Unfortunately, your car’s Tire Pressure Monitoring System (TPMS) isn’t smart enough to tell whether you’ve got a flat tire or if you will just need to add air.

Our automotive team knows how to distinguish between a flat tire vs puncture, so read these tips to learn how to tell if flat tire is punctured.

1. Check the Tire Sidewall

One quick way to identify a punctured tire is by checking the sidewall of the part in contact with the ground. In case of a puncture, this section will be completely flat.

Check the Tire Sidewall

In other words, you will see a bulge on the sidewall. That’s because a punctured tire won’t maintain a layer of air between the wheel and the road.

How to tell if a tire needs air?

The sidewall won’t be significantly lower than the rest of the tire, which means there will be no way to notice by looking at the tire.

You’ll usually notice an underinflated tire through the TPMS indicator on your dashboard. Alternatively, you can manually check tire pressure using an air pressure gauge. If the pressure is found to be less than the standard recommended 32 PSI, then your tire(s) needs air.

2. You Might Be Required To Add Air Seasonally

Experts say that a typical car tire (in good condition) will lose about two PSI per month on regular driving. Suppose you undergo a few cycles of cold-to-hot temperatures. In that case, your tires will be under pressurized and require a fill-up.

Living in a colder state can be a problem as the air in your tires can drop by up to 25 percent below the recommended pressure. When that happens, the TPMS triggers a caution light on your instrument cluster. And in case you’re wondering, that’s how to know if tire is flat while driving — the TPMS warning light.

So, if you’re in a state where the weather changes drastically from season to season, you’ll need to refill your tires a few times each year. That’s due to the chemistry in the tires. When the temperature rises, the air particles expand and get more energized, increasing pressure. Conversely, when the temperatures drop, air particles condense, which lowers the pressure and shrinks your tires.

Thus, if you just noticed that your tires are slightly flat, it’s likely due to normal processes you have no control over. All they need is for you to add air to the correct pressure range.

3. Check the Number of Tires Flat

The probability that all your tires will become flat at once is extremely slight. Therefore, if you discover that all of them are low simultaneously, someone deliberately slashed them, or the cold air caught up with your car. If only one tire is flat, then it’s likely that you have a puncture to repair, but if it’s all flat, you need to add air.

Number of Tires Flat

Another way to know you have a flat tire while driving is if the steering wheel feels heavy. Driving with a flat tire will ruin your fuel economy, reduce your turning efficiency, and might even cause an accident. Thus, if you notice underinflation while at the wheel, pull over and call for roadside assistance.

4. Check the Frequency of Refilling

Is there only one specific tire you keep refilling over and over? If so, you most likely have a puncture. A tiny hole in the tire can break the air-tight nature of the car and allow the PSI to drop significantly. That might not occur in a few hours in case of a slow leak, but it could take days for you to notice the underinflation.

If this is the situation you’re going through, we recommend checking out your tire for a puncture. In other words, if the tire is flat and you didn’t realize a gradual decline, you’ve got a leak, and adding air will only fix the issue temporarily. The good thing is that you can patch the hole and avoid buying a new tire. A spare tire will also be handy, especially if you notice a problem while driving.

5. Check Your Tire Pressure

As mentioned, seasonal changes affect the pressure on your car tire. Furthermore, the tires lose some pressure during everyday driving. These, combined, can contribute to your tire getting flat in the long run.

However, there’s a threshold to that, especially if you’ve filled your tires recently. For instance, if the tire pressure is 29 PSI instead of the recommended 32 PSI, that’s not so bad. The difference is probably a result of the weather. You still need to add more air, though.

On the other hand, if the pressure readings are 10PSI, then there’s no way the weather is to blame. In that case, you have a flat, punctured tire.

6. Look for a Puncture

Sometimes, you may notice that your tire went flat overnight. If that happens, you’ll most likely have a puncture. If you have a flat, punctured tire, the best way to tell this for sure is to take it out and inspect it.

First, fill the tire with air. Next, grab a spray bottle containing soapy water and spray it all over the tire, concentrating on the tread.

Look for a Tire Puncture

Take note that the tire can lose air from the valve core, the valve, a nail in the thread, or the bead. If there’s a leak somewhere, you’ll see bubbles forming around the area as the air escapes.

Depending on the hole’s size, you can put air in and then hear a hissing sound, and the air leaks out. That is easier to do when out of the car. You can repair the leak yourself or bring it to a specialist.

If you can’t find the puncture, it doesn’t necessarily mean there isn’t one. It may be too small or in a hidden place. Bring the tire to a competent mechanic for a thorough check-up and fixing.

How Can I Determine if My Tires Are Flat or Just Need Air Based on the Low Tire Pressure Light?

If your low tire pressure light illuminates, you might wonder how to distinguish between a flat tire or just an air refill. To resolve the issue, start by checking the tire visually for any signs of damage or deflation. If everything looks fine, use a tire pressure gauge to measure the air pressure accurately. In case the pressure is low, you can try fixing low tire pressure light by adding air to the tire until it reaches the recommended pressure.


Learning how to tell if a tire is flat or just needs air, whether on a bike or a car, is easy, and we’ve discussed that above.

Let’s summarize our discussion:

  • A tire has a puncture if the sidewall is significantly flat and has a visible budge.
  • Tires lose pressure naturally with the changing weather.
  • Physically checking for a leak is one of the best ways to tell whether a flat tire is punctured or not.
  • Driving with a flat tire can ruin your fuel efficiency and even cause accidents.

You now know how to distinguish between a puncture and a natural pressure drop, so use this knowledge and act accordingly to resolve your low tire pressure issues.

5/5 - (16 votes)
Ran When Parked