Digital vs Dial Tire Pressure Gauges: Which to Buy

A tire pressure gauge is a small tool that does one job: it tells you how much air is in a tire. This guide compares the common types and explains how to use one so the number you read is the number that matters.

TireShopper does not test products. We explain how the types differ, so you can choose from listings yourself.

Michelin says a gauge reading is the only reliable way to confirm tire pressure. That makes the gauge worth getting right.

The three kinds of gauge

Continental describes three formats: analog dial gauges, digital gauges and pencil-style stick gauges.

Dial gauges

Dial gauges show the reading on a circular face and need no batteries. Continental says that makes them reliable and durable over time.

Digital gauges

Digital gauges use a backlit screen that Continental says gives clear readings in low light. They do need battery power. If you check tires in a dark garage or before sunrise, a backlit display is the feature to look for. If you want a gauge that will always work, remember the battery is part of it.

Pencil gauges

Pencil-style stick gauges are the most compact option. Continental says they can be harder to read and are slightly less accurate than the other two types. They fit in a glovebox, but that is the main thing going for them.

Accuracy and resolution

Accuracy is how close the reading is to the true pressure. Resolution is the smallest step the gauge shows. A gauge can display fine steps and still be off, so do not treat a more detailed display as proof of a more accurate gauge.

Continental says dial and digital models generally deliver more consistent accuracy than pencil gauges. In our research for this guide we did not find a tire maker or industry body that publishes accuracy figures by gauge type, so we do not give any here.

Michelin suggests buying a high-quality gauge and checking its accuracy with a tire professional. If a listing states an accuracy figure, treat it as the maker's claim.

What to check on the listing

• Pressure range. The gauge should read comfortably above the pressure you need. Toyo says that, size for size, light truck (LT) tires require higher air pressure than P-metric tires to carry equivalent loads, so a truck owner should check the gauge reaches the placard figure with room to spare.
• Units. Choose a gauge that shows PSI if that is the unit on your placard.
• Readability. Look at the face or screen size and, for digital gauges, whether it is backlit.
• Power. A dial gauge needs no battery. A digital one needs battery power.
• Valve fit. You press the gauge onto the valve stem, so a design that seats easily helps you get a seal.

Where the right number comes from

Use the vehicle maker's recommended cold pressure. Federal rules require a placard on the vehicle that lists it for the front, rear and spare tires. USTMA says it is on a label on the driver's door or in your owner's manual. Michelin says it is on the driver's door jamb and on some vehicles inside the fuel filler flap.

Not the number on the sidewall

The tire also has a pressure figure molded into the sidewall. Continental says that maximum is not the target operating pressure. Michelin says it is the maximum the tire can handle. Use the placard number.

If your vehicle carries heavy loads or tows, Michelin says the placard typically lists both a standard and a loaded pressure, and to use the higher loaded figure then.

Check cold

Driving heats the tires and raises the pressure. Continental says it can add several PSI, enough to skew your readings.

USTMA says tires are cold after being parked for at least three hours. Continental says cold means stationary for at least three hours, or driven under a mile at moderate speed. Michelin gives the same three hours, or less than a couple of miles.

Temperature also moves pressure. USTMA says it rises in warm weather and falls in cold weather by about one to two PSI for every 10 degrees. Michelin says a tire correct in summer may be low by midwinter, and suggests checking and adjusting in autumn.

How to use a gauge

Continental's steps are simple:

1. Park on level ground with cold tires.
2. Remove the valve cap and set it somewhere you will not lose it.
3. Press the gauge firmly onto the valve stem until the hissing stops. Continental says a proper seal is needed for an accurate reading.
4. Compare the reading with your placard number and add air if it is low.
5. Repeat for all four tires and the spare. Front and rear tires may need different pressures, so check each one on its own.
6. Put the caps back.

USTMA says to check tires at least once a month. Michelin adds before any long trip.

You need a way to add air. Continental says an air compressor is also necessary to correct pressure after measuring. Our guide to choosing a portable tire inflator covers that side.

A gauge is not the warning light

A TPMS light is a backup, not a replacement for a monthly check. Our guide to tire pressure and TPMS basics explains when the light comes on and why a tire can be low without it.

Where to look

These links go to Amazon search results, not to a particular product. You choose what to open and compare:

• Digital tire pressure gauges (Amazon search, opens in a new tab)
• Dial tire pressure gauges (Amazon search, opens in a new tab)