How Old Are My Tires? Reading the DOT Date Code

Find the code

Look on the sidewall for the letters DOT followed by a string of letters and numbers, the Tire Identification Number (TIN). Federal rules require it on tires sold in the United States. The full TIN may be on only one side, so check both sides, using a flashlight or a phone camera if needed.

The last four digits, often inside an oval or set apart from the rest, are the date code.

Read the date

The first two digits are the week of the year (01 to 52 or 53) and the last two are the year. NHTSA's example: 0308 means the third week of 2008.

Codes with only three digits come from tires made before 2000.

Why age matters

NHTSA describes tire aging as the rubber and other components changing over time because of use, storage and environment. It says you cannot detect aging just by looking at the tires, and that aging tires are more prone to failure.

According to NHTSA, the people most at risk are those whose tires wear out slowly or never: owners of recreational vehicles, 15-passenger vans, collector cars or other vehicles that are not driven regularly, and anyone with low annual mileage. Sun exposure, warm climates, poor storage and poor maintenance speed up aging, and NHTSA says it is a greater concern in the southern Sun Belt states.

When to replace

NHTSA lists several reasons to stop using a tire: tread worn to the minimum (the penny test), physical damage such as cuts, cracks or bulges, irregular wear from underinflation or overloading, and changes in how it performs, such as losing pressure, noise or vibration.

On age alone, NHTSA notes that some vehicle and tire manufacturers recommend replacing tires that are six to 10 years old, regardless of tread wear. Your owner's manual or the tire maker's warranty booklet may give a specific figure.

Don't forget the spare

Spares rarely get used, so they often outlive the tires around them. NHTSA recommends that a full-size spare not be used as a replacement for worn tires, except in an emergency such as replacing a flat. Check its date code and pressure along with the others.

Buying tires

A tire starts aging at manufacture, not when it is fitted. When you buy, it is reasonable to check the date code on each tire before it is mounted. Also run the tire's brand and model through NHTSA's recall lookup, and register your new tires with the manufacturer so you hear about any recall.

Slowing tire aging

You can't stop it, but NHTSA's maintenance advice helps: check pressure monthly when tires are cold, inspect for damage, rotate, balance and align as the vehicle maker recommends, and pay attention to the tire pressure warning light. For stored vehicles, keep tires out of direct sun and away from heat. Our tread and pressure guide covers the monthly check.

Common questions

How do I tell how old my tires are?

Find the DOT code on the sidewall and read the last four digits. The first two are the week and the last two the year. 1224 means the 12th week of 2024.

How old is too old for a tire?

NHTSA does not set a single age limit, but it notes that some vehicle and tire manufacturers recommend replacing tires six to 10 years old regardless of tread. Check your owner's manual and the tire maker's guidance.

Is it OK to buy tires that are a year old?

Tires age from the date of manufacture, so a newer date gives more service life before age becomes a concern. Check the code before installation and ask for newer stock if it matters to you.

What about a three-digit date code?

Tires made before 2000 used three digits (week and the last digit of the year). Any tire with a three-digit code is more than 25 years old and well past the ages manufacturers mention.