How Old Is Too Old for Tires? What Makers Recommend

Why there isn't one number

Search "how old is too old for tires" and you'll see 5, 6 and 10 years quoted with equal confidence. They aren't competing rules. They're different pieces of guidance from different organizations, and each one means something specific.

NHTSA's own TireWise guidance points back to the manufacturers: some vehicle and tire makers recommend replacing tires that are 6 to 10 years old, regardless of treadwear. So the useful question isn't "what's the law?" It's "what do the people who made my car and my tires say?"

Here's that guidance side by side, then how to find your tires' age and what to do with it.

What the manufacturers say

Two patterns stand out. The five-year mark is about inspection, not replacement: it's when the tire makers want a professional to start looking every year. And the 10-year mark is the outside limit the tire makers set, whatever the tread says.

When your vehicle maker and your tire maker disagree, the shorter timeframe is the one to plan around.

Find your tires' age

A tire's age starts at its DOT date code, the last four digits of the DOT number on the sidewall: two for the week, two for the year. Type them in to see where each tire sits against the guidance above:

Can't find four digits? The full DOT number may be stamped on only one side, often the inboard one. Our guide to reading the tire date code shows where to look. Check every tire, because a set that's been rotated, patched or partly replaced can have more than one age on it.

Do tires expire if they're never used?

There's no expiration date stamped on a tire, but the aging doesn't wait for the first mile. NHTSA's TireWise guidance describes tire aging as the rubber and other components changing over time due to service, storage and environmental conditions. A tire that spent years in a warehouse, a garage or a trunk is still aging.

That matters in three places:

• The spare. It rarely touches the road, so it's often the oldest tire on the car. Bridgestone's guidance is to check the spare and replace it if it's more than 10 years old, even if it appears new.
• A car that sits. Low miles don't mean young tires. A second car or a seasonal car can reach five years with most of its tread left.
• "New" tires. Unused doesn't mean freshly made. NHTSA's Tire Buyers' FAQ suggests checking the date code when you buy and knowing your vehicle maker's replacement timeframe. Look before the tires are mounted.

Age isn't the only clock

A young tire can still need replacing. Age runs alongside two other limits:

• Tread. NHTSA says to replace at 2/32 of an inch, where the wear bars sit flush with the tread. Our tread depth chart covers where AAA's 4/32 recommendation fits in.
• Damage. NHTSA's advice is to look for bulges, cuts and cracks when you check your tires. A bulge on a two-year-old tire is a reason to replace it, whatever the date says.

Whichever limit a tire reaches first is the one that counts.

What an age inspection looks for

Aging doesn't always show from the outside, which is why the tire makers ask for a professional to look once a tire reaches five years. A technician will typically check:

• cracking in the sidewall and in the grooves between tread blocks
• bulges, cuts and other damage on both sidewalls
• irregular wear across the tread
• anything you've noticed on the road, such as a new vibration
• the date codes, spare included

If the inspection finds a problem, the recommendation will be to consider replacing that tire. If it doesn't, the answer is to keep checking monthly and inspect again next year.

The Florida factor

Where a car lives affects how quickly its tires age. NHTSA's TireWise guidance lists exposure to sunlight and a warmer climate among the things that contribute to aging, and NHTSA's research found tire aging is a greater concern in the more southern parts of the Sun Belt states.

For South Florida drivers that's a reason to take the five-year inspection seriously rather than waiting on the 10-year mark. Our guide to Florida heat and tires covers what heat does day to day.

An age plan you can follow

Want a quick read on tread, age and damage together? Try Do I Need Tires Yet?. If it's time, shop by size and check the DOT dates on arrival.