How to Check Your Car’s Tire Pressure, Step by Step

01In short

To check tire pressure, find the pressure your vehicle maker recommends, measure each tire with a gauge while the tires are cold, add or release air until each one matches, and put the valve caps back on. It takes a few minutes and needs only an inexpensive gauge.

Properly inflated tires matter for more than comfort. The US government’s FuelEconomy.gov notes that keeping tires at the proper pressure improves gas mileage, and that properly inflated tires are safer and last longer.

02Find the right pressure for your car

The number you want is the vehicle maker’s recommendation, not the number molded into the tire.

• Look on the driver’s door frame. Most vehicles have a tire information sticker on the edge of the driver’s door or the door jamb. Some put it in the glove box or on the fuel door.
• Check the owner’s manual. It lists the same recommendation and explains any differences for heavy loads.
• Note front and rear values. Some vehicles recommend different pressures for the front and rear tires.
• Don’t use the sidewall number. The pressure printed on the tire’s sidewall is the maximum the tire can hold, not the right pressure for your car. FuelEconomy.gov makes the same point.

Pressure in the US is usually given in PSI (pounds per square inch).

03How to check tire pressure

1. Start with cold tires. Driving warms the air inside a tire and raises the reading, so check before you drive, or after the car has been parked for a few hours.
2. Remove the valve cap from the first tire and put it somewhere you won’t lose it.
3. Press the gauge firmly onto the valve stem. A short hiss as you push it on is normal. If the hiss continues, the gauge isn’t seated: press more squarely.
4. Read the gauge. A pencil gauge pushes out a marked stick; a digital gauge shows a number. Write the reading down.
5. Repeat for every tire. Check the spare too if your vehicle has one, using the pressure listed for it.

What you should see: four readings close to the recommended number. A tire noticeably lower than the others is worth watching, even after you top it up.

04Adding or releasing air

1. To add air, attach the pump or air machine hose to the valve stem and add air in short bursts, checking with your gauge between bursts. Built-in gauges on air machines aren’t always accurate, so trust your own.
2. To release air, if you overfilled, press the small pin in the center of the valve briefly with the gauge’s nub or a fingernail, then measure again.
3. Replace the valve caps. They keep dirt and moisture out of the valve.

If you have just driven to an air machine, your tires are warm and will read higher than they would cold. Recheck them with your gauge once the car has been parked for a while, and adjust again if needed.

05How often to check

A simple habit is to check once a month and before any long trip. It’s also worth checking when the weather changes sharply, because air pressure in tires drops as temperatures fall. Many newer vehicles have a tire pressure monitoring warning light; treat it as a prompt to check with a gauge, not as a replacement for checking.

Planning a longer drive? Our road trip checklist covers the other checks worth doing before you leave.

06Common mistakes to avoid

• Filling to the sidewall number. That is a maximum, not a recommendation.
• Checking right after a drive. Warm tires read high and can hide underinflation.
• Relying only on the warning light. It may only come on once a tire is well below the recommended pressure.
• Ignoring a tire that keeps losing air. It may have a puncture or a damaged valve that needs professional attention.

07When to see a professional

Have a qualified tire shop or technician look at a tire that loses air repeatedly, has a bulge or cut in the sidewall, shows uneven wear, or makes the car pull to one side. GuideRanger is an educational publication, not a vehicle service provider; this guide helps you understand the check, and your owner’s manual and a qualified technician remain the authority for your vehicle.

08The short version

Use the pressure on your door-frame sticker or in the owner’s manual, measure cold tires with your own gauge, adjust in short bursts, and put the caps back. Check monthly and before long trips.