Tire pressure and tread — Arkansas Permit Test

Tire pressure should be measured cold, and a cold tire is one that has not been driven on for at least 3 hours.

The pressure printed by the maker is for a cold tire, so a reading taken warm can fool you into letting air out.

Rather, a cold tire is one that has not been driven on for at least three hours.

Driving warms your tires and increases the air pressure in them, so measure pressure when the tires are cold or allow for the extra pressure in warm tires.

A warm tire reads high, and a driver who lets air out to match ends up with a tire that is too soft.

When you drive, your tires get warmer, causing the air pressure within them to increase.

In general, tires are not safe and should be replaced when the tread is worn down to 1/16 of an inch.

Tread pushes water out from under the tire, and with too little of it the car slides on wet or icy roads.

In general, tires are not safe and should be replaced when the tread is worn down to 1/16 of an inch.

To check tread depth, place a penny in the tread with Lincoln's head upside down and facing you; if you can see the top of Lincoln's head, you are ready for new tires.

The penny gives anyone a quick way to measure tread without a gauge, before a worn tire causes a skid.

If you can see the top of Lincoln's head, you are ready for new tires.

How long must a tire go without being driven on to count as cold for a pressure check?

At least 3 hours. The pressure printed by the maker is for a cold tire, so a reading taken warm can fool you into letting air out. Arkansas Driver License Study Guide, p.84: “Rather, a cold tire is one that has not been driven on for at least three hours.”