It’s not that you don’t care about your tires, but unless you have a monthly alarm set on your phone to check your tire pressure, it might be one of the last bits of routine vehicle maintenance that you think about.

Tire Pressure Q&A

(Pixabay / jarmoluk)

Though often neglected, the practice of checking tire air pressure is critical. If you neglect it, you could end up purchasing tires much earlier than expected, but that’s not all. Poorly inflated tires can also lead to:

  • A bumpy ride
  • Poor steering
  • Decreased responsiveness to braking
  • Lower gas mileage
  • A dangerous blowout (in the middle of nowhere or the middle of traffic #Murphy’sLaw)

What is tire pressure?

Let’s start with a little science lesson. Literally everything in the cosmos is matter, and all matter is made up of tiny particles that are constantly moving around. Depending on how closely packed the particles are, the matter takes the state of a solid, liquid, or gas.

As you can imagine, if you’re always moving around, you’re bound to bump into something else sooner or later, and when this happens, a little bit of heat is generated. When it’s hot, the particles are moving around a little more quickly, bumping into each other a little more often, and generating a little more heat – which starts the cycle all over again. This increased amount of motion elevates the pressure in that particular area.

In the case of your tire pressure, the air particles in your tires are constantly running into the walls of your tires which creates the tire pressure itself. This is why it’s so important to check your tire pressure when the tires are cool because the friction and heat generated from driving can influence the internal pressure and give you an inaccurate reading.

How do I know what tire pressure is right for my vehicle?

There are a couple of places that you can look to check your tire pressure, but you need to make sure that you’re looking for the recommended and not the maximum tire pressure. The number written on the tire wall is usually the maximum pressure that the tire can handle without bursting, but that shouldn’t be the pressure that you use to fill your tire. Instead, look for the recommended tire pressure level on the inside of the driver’s side door or your vehicle’s owner’s manual.

When is the best time to check my tires?

There isn’t a specific time of day to check your tires, but, as mentioned above, you should only check them when they’re cool. That means you haven’t gone anywhere yet for the day, or it’s been at least four hours since you’ve driven. If you follow these guidelines, the pressure in the tires should be settled enough that you can get an accurate reading.

How often should I check my tires?

It’s a good idea to get into the habit of checking your tires every month, but at the very least, you should check them quarterly and before any big road trips. The reason you should check your tire pressure during a change of season is because every 10 degrees more or less than the ambient temperature can influence your tire pressure one pound per square inch (1 psi). That means that if the temperatures range between fall and winter is 40 degrees or more, you could run the risk of significant under-inflation. Similarly, transitioning from winter to spring could lead to over-inflation. If your tire pressure is already higher than it should be and you run into an uncharacteristically hot day, your tires may even pop from over-inflation.

What about my Tire Pressure Monitoring System (TPMS) – won’t that warn me when I need to check my tires?

Both yes and no. Congress passed a law in 2007 that required all future vehicles to have a TPMS in an attempt to prevent accidents caused by under-inflation. That means that even with a functioning TPMS, if your tires are over-inflated, you will not get an alert because your TPMS only monitors under-inflation.

How do I check my tire pressure?

If at all possible, use a digital or dial-type gauge instead of the pencil-gauge because they get a more accurate reading. Unscrew the cap covering the pressure outlet, zero out your gauge, and then firmly press the gauge to the outlet, making sure to get a good seal. If the pressure is below the recommended level, use compressed air to fill up the tire until it is at the correct pressure. If it is over-inflated, there should be a little post on your gauge that you can press against the column in the center of the outlet to let a little bit of pressure out. Be sure to check each tire individually (including your spare) and not to just rely on how they look.

Your tires are just as crucial to your safety as your brake system, so it really pays off to monitor them closely. Try writing it on your calendar or setting a monthly reminder in your phone to help you stay on top of it.