# How to Decode a Tire Identification Number to Determine Tire Age

by Editorial Team
Rita Forsythe

Tire age is the most important factor to consider when buying new or used tires. Just because a tire is brand new does not ensure that it is safe to use on a vehicle. As tires age the rubber breaks down and begins to crack, which can result in devastating car wrecks. For optimum safety, do not buy tires manufactured more than six years ago, learn to decode tire identification numbers, and always determine tire age before you buy new tires.

### Step 1

Look for the Tire Identification Number branded on the sidewall of the tire to determine the tires age. The Tire Identification Number is preceded by DOT, which stands for Department of Transportation, and is 10 to 12 digits in length. You may have to check both sides of the tire to find the complete Tire Identification Number.

### Step 2

Locate the last three or four digits of the Tire Identification Number. Previous to 2000, three digits determined the tire age. Tires made since 2000 use four numbers to determine a tires age.

### Step 3

Since 2000

Determine the year the tire was manufactured by decoding the last two digits. For example, if the last two digits are "07", then the tire was manufactured in 2007.

### Step 4

Determine the week the tire was manufactured by decoding the first two numbers that makeup the last four digits in the Tire Identification Number. For example, if the last four digits of the Tire Identification Number are 2807, then the tire was manufactured during the 28th week of 2007.

### Step 5

Before 2000

Determine the year the tire was manufactured by decoding the last digit of the Tire Identification Number. For example, if the last digit is "3", then the tire was manufactured during the 3rd year of the decade. The problem with this system was that you could not determine during which decade the tire was made.

### Step 6

Determine the week the tire was manufactured by decoding the first two numbers that makeup the last three digits in the Tire Identification Number. For example, if the last three digits of the Tire Identification Number are 403, then the tire was manufactured during the 40th week of 1993 (or 1983).

### Step 7

Shop for newly manufactured tires by decoding the Tire Identification Numbers. A good rule of thumb is to purchase tires that are less than six years old for optimum safety.