Drivers check tire pressure by removing the valve cap and pressing the tire pressure gauge onto the valve stem. A hiss sound occurs but stops when the gauge is pressed down hard enough. The user reads the marks on the bar that pops out or reads the digital display.
A tire gauge measures the tire's pressure in pounds per square inch, abbreviated as PSI. Cars display the recommended pounds per square inch on the doorjamb on the driver's side or in the glove box. Users should follow the pressure printed on the vehicle, which may differ from the number printed on the tire.
Drivers should check the air pressure when tires are cold. After driving, the tires heat up, the air expands and the pressure reads higher. It is best to measure pressure in the morning or after the car sits for a few hours.
When pressing the tire gauge onto the valve stem, a fast and firm motion gives an accurate reading. Taking two or three readings helps get an accurate measurement. If the numbers are consistent, the reading is likely accurate.
Drivers should check tire pressure regularly. Correct pressure is necessary for fuel efficiency, safe handling and longer lasting tires.