Check tire pressure
Now, armed with your tire gauge and the recommended inflation pressure information, it's time to check your car tires' current pressure.
1. Look for the stem valve on the tire and unscrew the cap.
2. Press your tire pressure gauge squarely onto the valve stem. If
done properly, you will hear a bit of air come out as you press the
gauge against the valve. If the hissing sound doesn't stop, you are
holding the gauge at an angle and allowing air to escape the tire.
Just remove the gauge and try again.
3. Holding the gauge against the valve, read the pressure indicated on
the dial, readout or graduated stick that slides out the bottom of the
gauge, depending on the type of gauge you are using.
4. Compare your gauge reading to the recommended pressure and
make a note of the number of pounds the tire will need to bring it up
to the recommended pressure level, if necessary.
If pressure is over the recommended specification, use the gauge to
release air pressure from your tire by slightly pressing the gauge
fitting against the air valve.
Replace the valve stem cap.
5. Check the rest of the tires' pressure, including the spare tire.
6. Then, head over to the gas station to adjust air pressure as