How to check your tire pressure
Don’t take your tires for granted
According to a survey conducted by the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA), nearly 12 percent of the nation’s passenger cars have at least one tire underinflated by 25% or more.2 Considering tire pressure can affect things like handling, braking, riding comfort, mileage and safety, that’s a surprising statistic.
Many late-model cars are equipped with a tire pressure monitoring system (TPMS). This alerts you when one or more tires are significantly underinflated by displaying the yellow low-tire indicator on your dashboard.
Tip: Tires normally lose a small amount of air pressure every day. Left unchecked, that can add up to a problem.
The tire pressure gauge
Use a tire pressure gauge or sensor to check the psi of your tires. For an accurate reading, buy a quality one, either digital or analog dial type. A digital gauge is easier to use, as you can remove it from the stem valve to read the pressure. Don’t use a gauge affixed to an air hose, as that type is frequently inaccurate.3
You’ll find the recommended tire pressure for your vehicle on the tire pressure chart affixed to your inside doorpost (or sometimes it’s in the glove box). You can also find it in your owner’s manual. Be sure to check the tire pressure chart carefully. Some vehicles require all four tires inflated to the same psi. Others require a differential between the front and rear.
Tip: Ignore the psi printed on the sidewall. That’s just the maximum pressure your tire can hold.
How to measure
Temperature affects psi. Driving heats up the tires, which increases the psi. It’s best to check them in the morning while they are still relatively cold. You can also check them after your car has been sitting for a few hours or driven for just a few miles.
2.Unscrew the valve stem caps
Put them in your pocket or someplace safe so they won’t get lost.
3.Take a reading
Press your tire pressure gauge over the valve stem and push down firmly until you no longer hear hissing air escaping. If you’re using a manual dial gauge, do not let it up until you’ve taken your psi reading.
Screw the valve stem caps back on
4.Keeping the valve stem covered prevents air from seeping out.
Tip: Be sure to check all four tires at one time, and every once in a while check the spare.