Automotive Maintenance

AAA's guide to maintaining your tires

Measuring tire pressure with a dial gauge

Maintaining your tires is an unavoidable part of car ownership. 

Tires affect many other aspects of driving, including fuel economy, handling, braking, comfort, and weather safety. That's why proper tire care is essential: Neglecting it can reduce your tires' useful lifespan, lead to expensive problems, and make your car more dangerous to drive.

How to recognize irregular tire wear

Depending on how old your tires are and what they've been through, their wear may be subtle or obvious. An inspection of each tire’s tread is a good place to begin. A properly maintained tire will show even wear all over—any other pattern is a good indicator that something is wrong with the pressure, suspension, or alignment.

Illustration of an underinflated tire and an overinflated tire
  • Underinflation: Too little air in a tire causes the center to sag inward and make less contact with the road, so the edges of the tread wear down more quickly. 

  • Overinflation: Conversely, too much air causes the center of the tread to bulge outward, so it bears the brunt of road contact and wears down more quickly.
Illustration of tire wear on a misaligned tire and a cupped tire
  • Misaligned wheels: A misaligned wheel focuses friction on one side of the tire, leading it to wear down more quickly. 

  • Wheel balance/suspension: Worn-out suspension parts (usually shocks or struts) or wheel-balance issues allow a tire to bounce in and out of contact with the road, creating "scalloped" grooves known as cupping.
  • Vibrating, humming, or thumping: Such noises can indicate cupping, flat spots on a tire, out-of-balance wheels, or a tire with a separated internal belt.

  • Pulling to one side: If the car pulls to one side while driving at a steady speed, there may be an underinflated or damaged tire on the side it pulls toward.
Mechanic removing a car wheel to rotate tires

How regular rotation helps your tires

Front and rear tires handle different amounts of acceleration, steering, and braking wear. For example, the front tires on front-wheel drive cars absorb the brunt of both acceleration and braking, so to prevent them from wearing out faster than the rear tires, they must periodically be swapped to the back and the rear tires to the front. (The exact way the tires are rotated usually depends on whether the vehicle is front-, rear-, or all-wheel drive.)

Check your vehicle’s owner’s manual for mileage recommendations; rotation is usually recommended every 5,000–8,000 miles.

How to measure your tread depth

Tires depend on grooves in their treads to maintain traction and shed water on wet roads. Depth is measured in 32nds of an inch, with most new tires starting out at 10/32” or 11/32”. Measuring your remaining tread depth is one of the most important car inspections you can do. You should do it monthly to uncover excessive or uneven wear before it becomes a safety hazard. 

The easiest and most accurate way to check tread depth is with a dedicated tread depth gauge, available at auto parts stores. But if you have spare change handy, you can also use a quarter or penny to measure depth.

Inforgraphic explaining penny and quarter tests for tread depth

In many states, it’s illegal to drive on tires with less than 2/32” of tread, so seeing the top of Lincoln’s head means your tires need immediate replacement.

Even tires that pass the penny test may be worth replacing, however. AAA's research has found that all-season tires that pass the quarter test still exhibit an average increased stopping distance of 87 feet and about a 1/3rd reduction in handling ability compared to new tires. Tested side by side at 60 mph, vehicles with worn tires are still going 40 mph when vehicles with new tires have come to a complete stop.

Given these results and others, AAA suggests using the quarter test to determine when it’s time for new tires.

A hand putting air into a tire with an air hose

How to inflate your tires properly

Having the wrong tire pressure leads to uneven wear and lower gas mileage, so you should check your pressure at least once a month to make sure it’s at the manufacturer-specified level.
1. If you don’t already have one, get a tire pressure gauge. There are digital, dial, and pen-type varieties—the digital and dial models are easier to use.

2. Check the tires before driving the vehicle. Warm tires will give higher readings than tires at rest.

3. Remove the tire’s valve cap, put the gauge over the valve stem, and press firmly until there’s no air hissing out.

4. Note the tire's current pressure on the gauge. Compare it to the pressure specified by the manufacturer, usually found in the owner's manual and the driver's door jamb. 

5. If the pressure is below normal, add air, rechecking with the gauge that way you don't add too much. 

6. If the pressure is above normal or you overfill the tire, release air by pushing on the metal stem in the middle of the valve with a fingernail or pen.

7. Replace the valve cap and repeat for the other tires. If your vehicle has a spare tire, check it as well. Keep in mind that some spares require higher inflation pressure.

Hand measuring tire tread depth with a depth gauge

Tire maintenance checklist

Every month, you should:

  • Examine tire treads for signs of irregular wear.
  • Check tread depth with a depth gauge, quarter, or penny.
  • Check tire pressure, refilling if necessary.

Every 5,000–8,000 miles:

  • Have tires rotated to spread wear evenly 

When you get new tires:

  • Have wheel alignment checked and new tires balanced
Need an inspection, rotation, or new tires?

If you'd rather have a professional take a look at your tires, or you need more work done than you can do yourself, consider a AAA Approved Auto Repair shop. These shops are regularly inspected by AAA and offer member benefits.

Learn more | Find a facility

Discount Tire America's Tire logo
AAA members save with Discount Tire

AAA members get exclusive savings at Discount Tire and America’s Tire: Up to $40 off a set of new “better” or “best” tires, or a free tire repair (a $20 value).1 Buy a set of tires and you’ll get free air checks, tire inspections, tire repairs, rotation, and re-balancing.

Offer is only available to AAA members in Southern California, New Mexico, Tidewater Virginia, and the Kansas City metro area.  

Learn more

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