Tire Pressure How-To

Perhaps the most silent killer of fuel economy is low tire pressure. If your tires are low on air that means more rubber is hitting the pavement – which drastically shortens the life of your tires, by the way! Low pressure – softer tires – means each tire must make more revolutions to travel the same distance. Let’s assume a properly inflated tire takes 1,200 revolutions to travel one mile. A softer tire will not cover as much distance per revolution – so you’re rotating that tire 1,220 times to travel that same mile. That’s unnecessary gas use! To keep this from happening to you, here’s a step by step guide to checking your tire pressure!

First step is to pick your tool of choice. (fig.1) Tire pressure gauges come in all shapes and sizes – analog and digital. My personal favorite features a light up digital display, which is easy to use even at night. Pick the one that works best for you.

Second, you need to know what your tire pressure should be. Luckily, this is the easiest part. Instead of hunting through some owner’s manual, the recommended tire pressure is printed on the sidewall of your tire. (fig.2) The pressure is measured in PSI – or pounds per square inch. Now that you know what you’re looking for, let’s check that tire pressure.

Third, locate your valve stem. It’s a rubber piece that sticks out from your tire through the wheel. (fig.3) It’ll have a plastic or metal cap at the end of it (your valve cap). That cap will twist off and reveal the valve.

Fourth step: it’s time to actually check your tire pressure. Press your tire pressure gauge to the valve. (fig.4) You’ll hear a hiss as air rushes from the valve. Your gauge only needs a moment to read the pressure. So make sure you don’t release too much air from the tire!

Read your tire pressure gauge. Does the reading match the PSI printed on the side of your tire? If not, add air to the tire via the valve. If you add air – or let extra air out – make sure you measure the tire pressure again before replacing the valve cap.