Tire pressure is often overlooked but is a crucial aspect of vehicle safety. Even the best tire on the market will have performance issues if you underinflate or overinflate it. And while most of us know the disadvantages of underinflated tires because they are a more common issue, it is not spoken enough for overinflated tires.
From longer stopping distances to annoyingly harsh rides, overinflated tires can change your driving experience for the worse. But how could you overinflate a tire? Well, maybe you use an inflator that doesn't have a built-in gauge and went too far. Or, maybe the ambient temperature has grown significantly in only a few days (not uncommon due to global warming), which can also increase the pressure inside your tires.
To reach the desired pressure when your tires are overinflated, you will need to deflate them. But how do you let the air out of a tire? You arrived just at the right place to learn everything there is to know about overinflated tires and how to bring them back to their optimal state. So, without further ado, let's learn the deflating truth!
- Understanding Tire Pressure
- Tools Needed to Deflate a Tire
- Step-by-Step Guide on How to Let Air Out of Tires
- Tips and Tricks for Safe and Effective Tire Deflation
- Using the Tire Inflator at Your Nearest Gas Station
- Mistakes to Avoid When Deflating Your Tires
Understanding Tire Pressure
Tire pressure, defined as the amount of air in your car's tires, is measured in pounds per square inch (PSI) (bar or kPa in other areas of the world). Tire pressure is one of the most crucial things regarding automotive safety and efficiency.
Improperly inflated tires can significantly worsen the handling of your vehicle and also affect fuel economy, comfort, and tire durability. Thus, understanding how tire pressure works and why it's crucial can help you ensure the best performance and longevity from your tires.
1. Importance of Proper Tire Pressure
Proper tire pressure plays a vital role in ensuring your vehicle's optimal performance. Moreover, you can expect improved fuel efficiency thanks to reduced rolling resistance. Underinflated tires need more power to turn, which makes the engine work harder. In addition, correct tire pressure ensures that your tires wear evenly, prolonging their lifespan and saving you money in the long run.
But the single most important contribution of proper tire pressure is safety. When your tires are inflated to the correct pressure, it results in an optimal balance between handling and comfort, shortest stopping distances, and generally the sharpest handling.
In other words, you will be able to retain control of your vehicle more easily when you need to make an evasive maneuver, and thanks to the higher grip, avoid accidents from happening.
2. Risks of Overinflation
Many people lately overinflate their tires to improve fuel efficiency. This works, but the gains will be negligible – you'll be happy to see a 1 mpg improvement.
Meanwhile, your vehicle will be less safe to drive because the tire's surface that makes contact with the road (known as the contact patch) is reduced on an overinflated tire. As a result, the stopping distances will be longer, and you will have less grip to play with in the corners.
Automakers would be happy to make their cars as fuel efficient as possible – even a 1 mpg improvement will make them more competitive. Still, safety is always the number one priority when driving, and thankfully, automakers still value that more than fuel consumption numbers.
Crucially, though, you won't be saving money by overinflating your tires. Yes, the tailpipe emissions will be lower, but the running costs might be higher. That is because overinflated tires also tend to wear out more in the center of the tread, while underinflated tires wear more on the outer edges. This uneven wear can reduce the overall lifespan of your tires, resulting in a need for more frequent replacement.
And it doesn't end there. Overinflated tires are also more susceptible to damage from potholes, curbs, and various road debris because the excess pressure makes the whole tire more rigid. As a result, the tire isn't able to absorb impacts as successfully, which increases the risk of punctures, cuts, bulges, or a blowout.
But even if you are ready to live with all those compromises, the lesser comfort might be too much to bear. Overinflated tires are stiffer and, thus, don't absorb bumps very well, resulting in a very harsh ride. Even an increase of 2 psi can have a significant effect on ride comfort, with the passengers experiencing a much less comfortable journey.
For all those reasons, it is crucial to keep your tires at the manufacturer-recommended PSI (bar, kPa). To do that, you might need to let the air out of your tires sometimes, especially if you use an inflator without a built-in pressure gauge.
Tools Needed to Deflate a Tire
Deflating a tire requires only a few basic tools, and it's a process that can be easily performed at home or on the road if necessary. Moreover, you don't need any DIY experience – letting air out of a tire can be done by literally everyone.
With that said, equipping yourself with the right tools can ensure the process is carried out accurately and safely. Additionally, proper safety equipment can protect you during the process.
1. Basic Tools for Tire Deflation
To deflate a tire, you will need a tire deflation tool. Truthfully, you can do it with every sharp object, like a screwdriver. Just press it on the valve stem, and the air should start hissing out. Still, I strongly recommend a tire deflation tool for its precision and safety. A tire deflation tool allows you to control the amount of air released and helps prevent accidental damage to the valve stem.
With that said, by only using a tire deflation tool or a screwdriver, you won't be able to tell how much you deflated a tire. Thus, I recommend also having a tire pressure gauge, which you will use to measure the pressure inside the tire. There are several types of gauges available, including stick-type, digital, and dial gauges. Of these, digital gauges are typically the most accurate.
2. Safety Equipment
Safety should always be your number one priority when working on your car. Although letting air out of a tire seems like a harmless process, things can still go wrong. In this case, your eyes might be hurt due to dust or debris coming out of the valve.
Thus, you should always wear safety glasses when letting air out of a tire. Also, I recommend safety gloves to keep your hands clean and safe from rough surfaces, along with a flashlight/headlamp in case you are working in a poorly lit area. For the latter, even your smartphone's flashlight will do.
Lastly, it is crucial to have your safety vest on to ensure other motorists see you, which goes a long way in avoiding accidents.
With these tools and safety equipment at your disposal, you'll be well-prepared to safely and accurately deflate your tires as needed.
Step-by-Step Guide on How to Let Air Out of Tires
Letting air out of a tire is a very straightforward process that can be finished by almost everyone. All you need is to locate the valve stem, which is very obvious, then measure the tire pressure, let the air out of the tire, and measure the pressure again. Of course, you might need to repeat the process to ensure proper inflation.
1. With a Screwdriver or the End of a Key
- Step 1: Checking the Tire Pressure
Before even starting the process of letting air out of a tire, it is crucial to measure the pressure. By doing that, you will ensure that the tire needs deflating, i.e., it is above the manufacturer's recommended PSI (bar/ kPa). To do this, you will need a tire pressure gauge. It is a small and cheap device that you can keep in your vehicle's trunk.
Locate the valve stem – it will stick out of the wheel's rim and have a plastic cap on it. Remove the plastic cap. It's the entry and exit point for air in the tire. Ensure that the valve stem is clean and free of debris before removing the valve cap.
Then, put the end of the gauge's hose on the valve and make sure it is seated properly, i.e., no hiss is audible. You should then get a reading on the gauge.
An important thing to note is that you should always measure the pressure when the tires are cold, meaning the vehicle has not been driven for at least three hours. Temperature can have a huge effect on pressure – the more heat you add to the tire, the more the pressure rises. This will give you an inaccurate reading, meaning you might let air out of a tire that was perfectly fine.
- Step 2: Safely Releasing Air from the Tire
Once you've checked the tire pressure and located the valve stem, you can begin to let air out. To do this, you'll need a screwdriver or another small, blunt object like the end of a key, or even a pen. Insert the object into the valve, press lightly, and air should start escaping from the tire, accompanied by a hissing sound.
Remember that due to the higher pressure inside the tire, compared to the atmosphere, air will escape very quickly. Thus, whenever you let air out of a tire, it is crucial to do it in bursts. Moreover, I highly recommend re-checking the pressure after every few seconds to ensure proper inflation.
- Step 3: Re-checking the Tire Pressure
Re-checking the pressure a few times is crucial, especially if you don't have a tire inflator at hand (and if you read this article, you probably don't have one). So, repeat the process of releasing air and checking the pressure until your tire is at the desired pressure.
Remember, letting too much air out of the tire will cause underinflation, which is as bad as an overinflated tire.
2. With a Staun Tire Deflators
Staun is a company that produces automotive accessories and has some excellent deflators that allow you to let the air out of the tires to a desired PSI. This solves most of the issues when deflating a tire, as hitting the target requires a lot of patience and repetition. Here is how to use Staun’s deflators to reach the desired tire pressure:
- Setting the Staun deflator to the desired PSI
Staun’s deflators are pre-set from the factory to 18 psi, which is useful for off-road applications. However, if you desire a higher/lower value, you will need to reset the deflator before attempting to let air out of the tire.
To do that, you will first need to set your tires to the target pressure, i.e., the manufacturer-recommended pressure. It is important to do this when you purchase a Staun deflator because that way, it will be ready whenever you need it.
You can purchase numerous deflator kits and set them to specific values if necessary. One kit comes with four deflators inside, which should be enough for most people, though.
After you set your tires to the desired pressure, take the Staun deflator and screw the lock ring and the cap down to the lowest level. Screw the Staun deflator onto the valve stem. Since the deflator will be in its highest position, air will not come out of the tire.
Then, what you need to do is unscrew the cap on the deflator until you hear a hiss, i.e., air comes out of the tire. Then, turn it back a quarter turn or until the hiss stops. Once you’ve done that, screw the lock ring up until it reaches the cap. Make sure that you don’t turn the cap, as that would reset the value.
- Using the Staun Deflator
First, check the pressure before deflating the tire. Your tire might be at the right pressure, so make sure to check this before attempting to let air out. Then, locate the valve stem on the rim of the wheel: it is covered with a plastic cap. Remove the cap.
Then, you can attach the deflator to the valve stem and look at how it does its magic! The Staun deflator will stop once it reaches the desired figure, and you will hear no hiss anymore. Once that happens, it is safe to remove the Staun deflator.
Tips and Tricks for Safe and Effective Tire Deflation
Want some expert bits of advice on how to let the air out of a tire properly? Here is the role of temperature in tire deflation and how you can recognize when to stop releasing air.
1. The Role of Tire Temperature
You have learned by now that driving puts heat into the tires and thus increases the pressure. However, ambient temperature can also affect tire pressure, and in some cases, significantly. For example, a particularly hot day can increase the pressure up to 5 psi, which should go back to normal during the night.
In other words, tire pressure is like a living organism that changes constantly, so you should be aware of how and why it changes. Thus, if hot weather hits your area, the increased pressure will be due to the higher temperature and should go back to normal once the weather calms down. Of course, you should let the air out of a tire if the weather doesn't go back to normal and stays hot for prolonged periods because you don't want to drive on overinflated tires.
2. Recognizing When to Stop
Knowing when to stop releasing air is crucial to maintain the right tire pressure. Experts will know how much air is released with every burst, thanks to experience. However, once you do it a few times, you should be able to tell how much pressure is released with each 2-second or 3-second burst.
You could even measure that – let the air out of a tire for two seconds and then measure the impact it has on pressure. Then, you will know how many bursts you need to reach the desired pressure.
Using the Tire Inflator at Your Nearest Gas Station
You know what? You can also use the big tire inflator at (almost) every gas station to let the air out of a tire. Sure, they are built to re-inflate your tire, but they also have a deflator built in.
Moreover, most of them are digital – the only thing you need to do is locate the valve stem, attach the hose, and choose the target pressure. The system will do everything for you, i.e., inflate or deflate the tire if necessary.
Mistakes to Avoid When Deflating Your Tires
Although deflating a tire is a simple process, you can easily miss the pressure target, which could result in worse handling, efficiency, and safety.
1. Avoiding Excessive Deflation
The single most error people make when letting air out of a tire is over-deflation. This can be problematic, as underinflated tires are a significant safety issue on their own. Moreover, they lead to worse fuel economy, less responsive steering, and shorter tire lifespan.
Some people underinflate their tires for smoother ride quality. Still, I would advise against it, as it is not worth it when you consider all the other disadvantages. Besides, your car's suspension was designed to work with the tire pressure recommended by the manufacturer, and decreasing it might not have a significant effect on the ride. In fact, in some cases, the ride might be less composed, especially when you hit a big bump.
Therefore, it's important to check your tire pressure frequently during deflation to ensure you don't go below the manufacturer's recommended level.
2. Ensuring Even Tire Pressure
Another common mistake is failing to ensure even tire pressure across all tires. Uneven tire pressure can lead to imbalanced handling, uneven tire wear, and potential vehicle instability. It's crucial to check and adjust the pressure in all four tires, not just the one that appears to be overinflated.
Mastering tire pressure is very easy and, honestly, should be done by every driver, especially knowing how to let air out of tires. By ensuring that your tires are properly inflated, you also act on other systems in your car and ensure that they also work properly. The modern vehicle is a complex system, and any variation will make it work sub-optimally.
And ensuring that your vehicle is in its optimal state will bring benefits to you as well. By caring for your tires, you ensure your safety but also your finances – improperly maintained tires are much more expensive to run.
Your reward will be a more reliable, efficient, and safe vehicle and newfound confidence in your ability to handle minor maintenance tasks like tire deflation. It's a stepping stone toward greater automotive knowledge and a very important one!
I’m Ivo Gievski, the content writer for Tireer. We built our website with over 15 years of experience and extensive research in the automotive and technology sectors. My dedication to delivering high-quality content is unwavering, and I strive to continuously hone my skills to stay ahead of industry trends and provide readers with informative, engaging, and valuable insights.