How To Check Air Pressure In Tires


Tire inflation is something that is neglected by many drivers, and it’s easy to understand why. Modern radial tires deform very little until they are drastically low on air pressure. A tire can be as much as 30% underinflated and still look completely normal. But why is proper inflation so important?

  • Underinflated tires have increased rolling resistance, which can affect fuel economy.
  • Increased rolling resistance will also lead to overheating, which can be downright dangerous and possibly cause tire failure on a long highway trip.
  • Underinflated tires will affect your car’s steering, drivability, ride and handling. If your car’s steering seems heavy and clumsy, or if your vehicle is pulling to one side or the other, the first thing you should check is tire pressure…before alignment or any other mechanical issues.
  • Underinflated tires can lose as much as 25% of their tread life.

Overinflated tires aren’t good either! Overinflated tires are unusually stiff, making them ride more harshly and can be more susceptible to damage from potholes, curbs and road debris. Overinflated tires will also wear unevenly, with tread wear concentrated at the center.

Fortunately, the solution is easy enough.

Check your tire pressure at least once a month – even brand-new tires are porous and will gradually lose pressure under normal wear. Also remember that air pressure will change somewhat according to temperature; air being a gas, it will expand as temperatures go up. The most accurate readings will come in early morning, when ambient temperatures are cooler and the tires haven’t had a chance to heat up yet. You can go by either the recommended inflation in the tire’s literature, or by the recommended pressure stamped on the sidewall of the tire itself.

Don’t rely on the tire pressure gauge that’s built in to the air hose at the gas station – those can be pretty inaccurate. Spend a few dollars and get a quality tire gauge, then keep it in your car’s console or glovebox. The old-style pencil-type gauges are inexpensive and can give you reasonably accurate readings; newer gauges register the reading on a dial or even a digital readout for the most reliable results.

Tire pressure can be a crucial element for several different reasons; with gas over $3 per gallon, that’s reason enough by itself to pay attention to it. The good news is, it’s an easy enough thing to keep tabs on and costs very little to maintain!