Mark it once you can do it without this page open.

How to do it

  1. Look up the pressure your car needs on the placard in the driver's door jamb or in the owner's manual; front and rear can differ.
  2. Check in the morning or after the car has sat for three hours, because driving warms the air and raises the reading.
  3. Unscrew the valve cap, press the gauge straight onto the valve stem, and read the number.
  4. Add air in short bursts and recheck until you reach the sticker number; press the valve pin briefly to let air out if you overshoot.
  5. Put every valve cap back on, then check the spare the same way.
  6. Push a tread depth gauge into the shallowest groove across the tire, or look for wear bars sitting flush with the tread.
  7. Look along each sidewall for bulges, cuts or cracks, and across the tread for nails or uneven wear.

Common mistakes

  • Filling to the maximum pressure printed on the sidewall, which is a limit, not the target.
  • Checking right after a long drive and letting air out of warm tires.
  • Trusting the dashboard warning light alone; it often comes on only when a tire is well under.
  • Forgetting the spare until the day you need it.

Quick self-check

Three questions. Your last score is kept in this browser.

1. Which pressure should you fill to?
2. When is a pressure reading most accurate?
3. The wear bars in the grooves are level with the tread. What does that mean?

Teach this to someone

A one-page sheet for showing a friend, a roommate or a kid: what to say, what to show, and one question to check it landed.

Words on this page

Sources

  • Your vehicle's owner's manual, for your model year. Checked September 28, 2026.
  • National tire safety guidance for drivers, current edition. Checked September 28, 2026.

Last reviewed . First published .