A man checking the tire pressure on his vehicle.

Routine tire checks improve safety and help boost fuel economy. Perform these checks monthly and before you embark on a long-distance trip.

Check the Tire Pressure

Tires lose air over time. They need to be checked monthly and filled every so often, especially when temperatures drop in winter months. Underinflated tires flex more than properly inflated ones. That builds up heat, which can lead to failure. Plus, underinflated tires are less fuel-efficient and can wear out faster.

More on tires

To get a good tire-pressure reading, check when the tires are “cold,” meaning the car has been parked for longer than 3 hours. Consult your owner's manual and the driver's doorjamb placard for the proper pressure. If you have a spare tire, check its pressure regularly, too.

Scan the Tire Sidewalls

Look for cracks caused by age and exposure to the elements. Encounters with curbs, potholes, and other unfriendly objects in the road can lead to cuts and bulges in tires. Replace tires that show any signs of trouble and you’ll head off problems before they occur.

Check the Tire’s Age

The date code tells you when the tire was manufactured. Look for “DOT” followed by several digits near the wheel. The last four numbers identify when the tire was made. For example, “0308” indicates that the tire was manufactured in the third week of 2008. Consult your owner’s manual for when to replace it. Some vehicle manufacturers recommend replacing tires after six years. Without a limit, we recommend removing tires at 10 years, including the spare, regardless of condition.

Measure Tread Depth and Wear

Grab a quarter and a penny to measure tread depth. Place the quarter upside down in a tire groove with a treadwear indicator—raised bars within some grooves. They will appear flush with the tread when the tire is worn out. The distance from the quarter’s edge to George Washington’s hairline is about 4⁄32 inch. If you can see all of Washington’s head exposed, it’s time to start shopping for new tires—you at least still have some grip left. And if there is some space exposed above George’s head, check the tire with a penny. Using the same technique, insert that penny into the same groove, and point Lincoln’s head down. If you can see the top of Abe’s head over the tread, the tire should be replaced immediately. Many states have made it illegal to use tires with a tread that shallow.

Editor's Note: This article also appeared in the November 2018 issue of Consumer Reports magazine.