How should you assess your tire pressure?

How should you assess your tire pressure?

• A. With a caliper
• B. With a ruler
• C. By feel alone
• D. With a pressure gauge

Answer: (D)

Check tire pressure with a pressure gauge because it gives an exact reading of the air inside the tire. A caliper measures thickness, not pressure, and a ruler measures length, so neither will tell you the correct psi. Relying on how the tire feels by hand is unreliable, since you can’t judge the exact pressure and safety depends on an accurate value. Readings should match the recommended pressure found in the vehicle’s manual or on the door jamb sticker. For the most accurate result, check when the tires are cold, since driving heats tires and raises the pressure. If the reading is low, add air until you reach the recommended level; if it’s high, release air to bring it down. It’s also good practice to check the spare with the same gauge.

Check tire pressure with a pressure gauge because it gives an exact reading of the air inside the tire. A caliper measures thickness, not pressure, and a ruler measures length, so neither will tell you the correct psi. Relying on how the tire feels by hand is unreliable, since you can’t judge the exact pressure and safety depends on an accurate value. Readings should match the recommended pressure found in the vehicle’s manual or on the door jamb sticker. For the most accurate result, check when the tires are cold, since driving heats tires and raises the pressure. If the reading is low, add air until you reach the recommended level; if it’s high, release air to bring it down. It’s also good practice to check the spare with the same gauge.