Travel Smart: How to Check Your Tire Air Pressure

By Sarah Lipoff

Updated on 7/19/2014 at 8:00 AM

In addition to being a driving hazard, underinflated tires wear the sides of the tire and add to your gas bill. Overinflated tires, on the other hand, wear more quickly overall and have an increased potential for a blowout. It's suggested by the DMV to keep tires no more than five pounds per square inch below or above what is recommended for your tires, but how do you know?

You can check your tires in the comfort of your own driveway, but it's a great idea to do the procedure right in front of your local gas station's air pump. And most offer free air with purchase of gas. It's best to check air pressure first thing in the morning while the tires are cool. Warmer air expands, so you won't get a correct reading.

  1. Be smart and pick up a gauge, which aren't very expensive, and keep in your glove box so you always have one on hand. The gauge measures pounds per square inch (PSI) to help you make sure your tires are just right.
  2. Before getting started, check your car's manual and find out what the recommended PSI is for your tires.
  3. Remove the tire cap from the tire's valve and put in your pocket — you don't want to lose it! Position the tire gauge on the valve stem, which is round with a metal rod in the middle. You want to avoid releasing any air, so firmly press straight down on the stem to secure the gauge.
  1. Watch the tire gauge until it stops and check the number against what is suggested for your tire. Do the same for all four tires, noting which tires need air and which are OK as is.
  1. To fill tires with air, follow the same technique for using the tire gauge and firmly press straight down with the air hose. Press the handle to activate the air.
  2. After a few seconds of adding air, remove the air hose and check pressure using the tire gauge. Continue until all four tires are at the proper PSI.
  3. Replace the tire stem caps and your car is ready to go! Coordinate checking your tires with your big monthly gas-tank fill-up and your tires will last longer — and drive better.