Tires that are not inflated properly may wear excessively, which is one of the reasons it’s important to know how and when to check your tire pressure. Cars.com says tires with the incorrect pressure may lead to lower gas mileage and negatively impact your car’s handling. Here’s how to check your tire pressure, from finding your vehicle’s recommended tire pressure to filling tires with air.
How to Find the Recommended Tire Pressure
Your vehicle’s recommended tire pressure can typically be found on a sticker inside the driver’s door. It’s also usually listed in the owner’s manual, says Cars.com. Tire pressure is measured in pounds per square inch (psi).
You may also notice that the sidewall of the tires lists a tire pressure. Consumer Reports says this is the maximum tire pressure allowed. You should go with what’s listed on the door sticker or owner’s manual, as this is the ideal tire pressure for your vehicle.
How to Check Tire Pressure
You will need a tire pressure gauge, which you can find at most service stations or auto parts stores. Edmunds states you should check the pressure when the tires are cold, as the friction from driving causes them to heat up and affects the pressure. Check them first thing in the morning or, if you’re already driven the car, Consumer Reports recommends waiting at least three hours for the tires to cool down.
Once you have a tire gauge in hand, Edmunds says this is how to check your tire pressure:
- Remove the cap from the air valve on the tire, and put it somewhere you won’t lose it.
- Press the tire gauge against the open valve stem for a second or two. It’s normal to hear a hiss of air.
- Read the air pressure gauge. For manual gauges, a dial points to the pressure or a bar indicates the pressure by how far it was pushed out. The pressure will appear onscreen on a digital tire gauge.
- Compare this number with the recommended tire pressure.
- Replace the tire’s air valve cap. (Hold off on this step if you need to adjust the air pressure.)
- Repeat this process for each tire.
How to Inflate Your Car’s Tires
If your tires are lower than the manufacturer’s recommendations, follow these steps from Edmunds to inflate the tires:
- Park close enough to the air compressor so you can reach all four tires with the hose.
- If the valve caps are still on, remove them.
- Press the hose nozzle down on the valve stem. Air may flow automatically or you may need to press a lever. You should notice the tire inflating and feel air flowing through the hose.
- Remove the hose fitting or release the inflation lever. Check the air pressure, as described above, using the gauge on the hose or your own tire gauge.
- Repeat steps 3 and 4 as needed until the tire is inflated to the correct psi.
- Repeats steps 3-5 for the vehicle’s other tires.
- Once the tires are inflated properly, replace the valve caps.
Tip: If you hear or feel air coming out of the hose nozzle while you’re trying to fill the tire, Cars.com says you should check that it is properly connected to the tire valve stem.
How to Release Air from Tires
You don’t want to have tires that are overinflated, as this can lead to poor handling, says Cars.com. The Family Handyman notes that overinflated tires are more prone to skidding and hydroplaning.
If your tires are reading more than the recommeneded psi, Cars.com recommends the following steps to release air:
- Briefly press the small dot or bead on the back of the tire pressure gauge into the center of the valve stem on the tire. You should hear the air escaping the tire.
- Use the gauge to check the tire pressure.
- Repeat these steps until you’ve released enough air to reach the correct psi.
Tip: As you near the correct pressure, release smaller and smaller amounts of air until you get to the appropriate psi, says Cars.com.
When You Should Check Your Tire Pressure
Tire air pressure should be checked once a month using the same tire gauge, says The Family Handyman. Remember to check when the car has been parked for at least a few hours and the tires are “cold.” Tire pressure can vary 1-2 pounds per square inch (psi) for every 10-degree difference in ambient temperature, says Car Talk — the psi typically rises in the summer heat and drops when it’s cold outside. If you’re in the habit of checking your tires every month, you can adjust the pressure as it fluctuates throughout the seasons.
Car Talk recommends checking your tires regularly even when they look fine. Also, check them if you’ve run over a sharp object or hit a curb. It’s a good idea to have them checked when you bring your car in for routine service, says Car Talk.
Your tires are one of the most important parts of your car. They’re literally the place where the rubber meets the road. Regular care and maintenance can be essential to the safe and reliable performance of your vehicle.
Originally published April 28, 2017.