Choosing and using a tire gauge

In his article on tire gauges, Steve Larson of Motorcycle Consumer News gives this important advice: "Buy a good gauge, take care of it and you won't regret it." The amount of air in your tires affects how much of your tire touches the ground. The wrong tire pressure -- whether it is too much or too little -- can change the way your car handles on the road, leading to an uncomfortable ride or even unsafe handling. It can also wear out your tires faster and give you poor gas mileage.

Tom and Ray Magliozzi, columnists and hosts of the radio program "Car Talk," classify checking your tire pressure as one of the easiest auto maintenance duties. Most importantly, they say, start with an accurate tire gauge that is easy to use.

Some brands list a measure of accuracy. For example, if your tire gauge says that it is rated at +/- 5 percent, then a reading of 30 psi means that your tire pressure is between 28.5 to 31.5 psi. Buying a gauge with a lower number on that accuracy rating ensures that your measurements are as precise as possible.

Most tire gauges only display the tire pressure measurement while the gauge attached to your tire's valve stem. This means that you need to be able to see the tire gauge display while it is still on the tire to read the measurement. Some gauges feature a hold button, which "holds" the reading after you remove the tire gauge, but this option typically comes on more expensive models.

Once you find the right tire gauge, make sure you are using it correctly and often. Experts recommend that you check your tire pressure at least once a month and only when your tires are cold. To get a good reading, press your tire gauge firmly onto the valve stem. Though a little air may leak when you push on the gauge, you shouldn't hear any loud hissing after that. Refer to the sticker in the doorjamb of the driver's side door (it's placed there by the manufacturer of your car) to find the recommended tire pressure for your tires.

Tire gauge prices range from a couple of dollars for a basic stick tire gauge to a few hundred dollars for a professional model. Though higher-priced tire gauges sport more features, reviewers say they're overkill for most drivers who just want to quickly and accurately check their tire pressure.  Fortunately, there are plenty of affordable options.

Things to consider when buying a tire gauge:

  • Accuracy is key. After all, there's no point in measuring your tire pressure if you're not getting an accurate reading. Resist the urge to buy a stick gauge at the gas station and purchase a quality digital or dial tire gauge instead. The extra hassle of picking up an accurate gauge will save you in the long run.
  • Get a gauge that is easy to read. Make sure that the number, whether digitally displayed or on an old-fashioned dial, can be seen clearly. Remember that you will be reading the gauge while it is still attached to the tire.
  • Consider the range you will measure. While most passenger cars need a tire gauge that reads up to 60 psi, larger vehicles and heavy-duty trucks use more air pressure in their tires and require a gauge with a higher range. Some equipment tires, such as tractor tires and tires on bicycles or wagons, require a very low or very high pressure gauge.
  • Select a gauge that is easy and comfortable to use. If you wind up with a bulky or awkward gauge, chances are that you won't use it as often as is recommended. Small gauges take one hand to use, while dial gauges with attached hoses require two hands to operate properly. The gauge's handle should also have enough grip to allow you to push the gauge firmly onto the valve stem.
  • How easy is it to reach your valve stem?  For most tires, standard gauges work fine. But for some motorcycle tires or specialty rims and hubcaps, valve stems can be difficult to reach. Consider a dial gauge with a flexible hose or a digital gauge with a thin, angled head if your valve stem is hard to access.

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