How to Check Tire Pressure

By the Mercury Team

Maintaining proper tire inflation is an essential part of general car maintenance. It helps extend your tires’ lifespan, offers better handling, and improves gas mileage. The best way to ensure your tires are properly inflated is to check your tire pressure periodically. In this blog, we’ll explain where to find your car’s recommended tire pressure, how to check the pressure, and how to inflate and deflate your tires.

Recommended Tire Pressure

The recommended tire pressure varies depending on the type of vehicle and tire, but generally, most passenger cars fall between 32 and 35 pounds per square inch (psi).

You can usually find your vehicle’s recommended tire pressure printed on a sticker inside the driver’s door. This label should provide tire pressure specifications for the front, rear, and spare tires. You can also check the owner’s manual for tire pressure specifications.

You might also notice that the side of your tires offers a psi reading of the maximum tire pressure allowed. While keeping this maximum pressure in mind is important, you should still follow the recommended pressure on the sticker or in the owner's manual.

How to Check Tire Pressure

To check your tire pressure, you’ll need a tire pressure gauge, which you can get at most department or auto parts stores. It’s especially important to check the pressure in the winter because tire pressure can decrease about 1 psi for every 10-degree drop in temperature. Why does tire pressure go down in cold weather? In colder temperatures, air molecules usually move slower and have less impact on the tire walls, leading to a drop in pressure. The opposite is true for heat — the higher the temperature, the more tire pressure increases. How much heat can tires withstand? Generally, a tire’s temperature should not exceed 195 degrees Fahrenheit.

Regardless of the season, it’s best to check your tire pressure once a month first thing in the morning before driving your car. Why? You’ll get a less accurate reading if your tires are warm from driving.

Once you have your gauge, follow these steps to check your tire pressure:

1. Remove the cap on your tire’s air valve and set it aside so you won’t lose it.
2. Take your tire gauge, place it over the valve stem, and push it into the stem until you hear a hissing sound.
3. Check the reading on your gauge. For manual gauges, a dial points the pressure or a small bar pushes out to show the pressure reading. A digital gauge shows the pressure reading on the screen.
4. Compare the reading with your car’s recommended tire pressure.
5. If the reading matches the recommended psi, screw the cap back onto the valve. If not, put air in your tire.
6. Repeat these steps for each tire.

How to Put Air in Tires

If your tire pressure is lower than the manufacturer’s recommendations, you need to inflate it. Most gas stations will have an air compressor where you can inflate your tires. Follow these steps once you park your car close enough to the air compressor where the hose can reach all four tires:

1. Remove the valve cap and put it in a safe place.
2. Press the hose nozzle down on the stem for about 10 seconds. You should see the tire inflating and feel air flowing through the hose. If you hear a hissing sound while filling the tire, ensure the nozzle is properly connected to the stem.
3. Remove the nozzle and check the tire pressure using your gauge.
4. Repeat steps 2 and 3 until your tire reaches the recommended psi.
5. Screw the cap back into place.
6. Repeat this process for your other tires.

How to Release Air from Tires

When filling air in your tires, you may overinflate them. Overinflated tires can lead to multiple problems, including poor handling, accelerated tread wear, and possible skidding and hydroplaning. Luckily, you can easily release air from your tires. Here’s how to do it:

1. Unscrew the valve cap and set it aside.
2. Take a flathead screwdriver or any thin, long blunt tool, press it into the center of the valve stem, and hold it there for a few seconds. You should hear air escaping the tire.
3. Release your tool and check the tire pressure with your gauge.
4. Repeat steps 2 and 3 until you reach your recommended psi.

Conclusion

Checking your tire pressure at least once a month is a key component of general car maintenance. Properly inflated tires help maximize fuel economy, minimize tire wear, and provide better handling to keep you safe behind the wheel. Another way to stay safe on the road is by purchasing car insurance from Mercury, where we offer best-in-class coverage at an affordable rate.

Contact us today for a fast, free quote!