For maximum safety, the tires on your car should always be inflated to the recommended pressure. Most people don’t know this, but more than 11,000 crashes in the USA each year are tire-related, and they contributed to 738 casualties in 2017, according to NTHSA.
And, most of the time, this happens due to incorrectly pressurized tires. Even if you have the best tires on your car, they won’t work well if they aren’t inflated properly. Fortunately, checking the tire pressure is very straightforward – here is how to do it!
Consequences of Underinflated and Overinflated Tires
The implications of incorrectly pressurized tires aren’t only anecdotal – they are a fact. Moreover, people lost their lives because Ford recommended low tire pressure on the Firestone tires of its 90s’ Explorer model.
As a result of that, the tires started disintegrating at highway speeds, which resulted in many accidents and 271 fatalities. This engineering fiasco taught us a critical life lesson – we should always drive on tires with correct tire pressure.
When the tires are underinflated, the structural rigidity of the rubber is much lower, or in layman’s words, the casing is softer. Because of that, the tire can’t carry the weight of the car and succumbs under pressure.
More accurately, the tires are much less stable in the corners and are very unresponsive. Moreover, degradation takes a much larger toll – expect premature wear. So, it’s not only dangerous to drive on underinflated tires – it’s much more expensive as well.
It’s almost the same story with overinflated tires. In this case, the tires will bounce from the surface on every bump, which can severely worsen the stability and stretch the braking distances. Furthermore, the tread of the tires will wear unevenly.
For all those reasons, you should check the tire pressure at least once a month if you drive mostly in urban environments. Additionally, each time you go on longer trips, you should check the tire pressure first.
When is the Best Time to Check the Tire Pressure?
The pressure inside your tires changes with temperature – that’s how physics work. Typically, you should expect around 1 PSI (0.06 Bar) of pressure added with an increase of 10 °F (12 °C). Moreover, tires get warmer as you use them.
For those reasons, I strongly recommend checking the tire pressure on cold tires. To be more precise, you should check the pressure on cold tires, preferably in the morning. Don’t worry about the pressure increases while you drive – car and tire manufacturers take that into account.
If you check the pressure on warm tires, the reading will be accurate, yes. However, the pressure will fall below the threshold once the tires cool down. Hence, make sure that you check the pressure only on cold tires.
Also, you need to make sure that you measure the pressure when the vehicle is unloaded. As soon as you add weight to your car, the pressure will increase.
Where to Find the Correct Pressure for Your Car?
Car manufacturers usually put a sticker with the correct tire pressure on either the driver’s or passenger’s door sill. If you can’t find it there, you can check in the user’s manual.
Now, when you check the readings, you’ll see a minimum and maximum tire pressure. The minimum tire pressure is reading for an unloaded car (e.g., without passengers or cargo). The maximum tire pressure, on the other hand, is meant for reading with a loaded vehicle.
For most passenger vehicles, the correct pressure varies between 32 and 35 PSI (2.2 to 2.4 Bar).
What’s the Difference Between PSI, kPa, and Bar?
PSI is based on the imperial measuring system and means “pounds per square inch.” kPa (kilopascal) and Bar, on the other hand, are based on the metric system and the “Pascal” unit.
It would be best if you always made sure that the readings on your gauge are the same as those in your car. The PSI reading isn’t interchangeable with kPa and Bar – it merely uses a different measurement system.
The metric units are interchangeable, though – 1 Bar equates to 100 kPa (average atmospheric pressure). So, if the reading on your gauge shows 2.2 Bar, it equates to 220 kPa.
Items That You’ll Need
You will only need a pressure gauge to check your tire pressure. However, for correct measurement on all four tires, I recommend having a pen and paper on hand or use your smartphone.
How to Check the Pressure?
First, park your car on a level surface. Otherwise, you might not get the correct readings from each tire. Then, prepare your tools, and you’re good to go!
Step 1. Unscrew the Valve Stem Cap
The first thing that you need to do is to unscrew the plastic cap that sits on the valve stem. The cap won’t release any pressure, but it’s still an important piece that keeps the Schrader valve clean. Once you remove the cap, make sure that you place it in a safe place.
Step 2. Place the Pressure Gauge on the Valve Stem
Take the tire pressure gauge and place the hose on the valve stem. Press as hard as needed for the hissing sound to stop. Otherwise, the gauge won’t get the proper reading, and the tire will lose pressure.
An analog gauge should immediately show you the correct pressure inside the tire. However, if the indicator is digital, you might need to press a button for the reading to start. Either way, it should only take a few seconds.
Step 3. Write Down the Reading
Once you checked the pressure on the tire, write down the reading. For straightforward comparison, you might first want to write down the recommended tire pressure, and next to it, the reading from the gauge. That’s especially true for cars that have different tire pressures on the front and rear tires.
Step 4. Repeat on Other Tires
Repeat the same process on all tires, write down the readings, and compare them to the factory-recommended ones.
Checking the tire pressure on your car is very easy and quick, yet it will make your driving much safer. Also, don’t be that person that can check the correct pressure only by visual inspection of the tires. It’s impossible, trust me!
And, if something wasn’t straightforward enough, please do not hesitate to ask a question in the comments section – I’ll be happy to answer. Moreover, if you found this article useful, share it with your friends – it’s essential for the safety of all traffic participants.