When Should You Retire Your Tires?

 

For years, people have relied on a tire's tread depth to determine its condition. But the rubber compounds in a tire deteriorate with time, regardless of the condition of the tread. An old tire poses a safety hazard.

In finding the age of tires on your vehicle, you must look at the sidewall of a tire. The sidewall is littered with numbers and letters, they all mean something, but deciphering them can be a challenge. For determining the age of a tire, you'll need to know its U.S. Department of Transportation (DOT) number: DOT XXXX-XXX-XXXX which tells the manufacturer plant code, size, brand, week and year of the tire. 

For determining the age of a tire look at the last digits of the DOT. The first two numbers represent the week in which the tire was made. The second two represent the year. A tire with a DOT code of 0812 was made in the 8th week of 2012.

After checking out a tire's birth date, give the rubber a visual inspection. Check tires regularly for any sign of aging, such as tread distortion or large or small hairline cracks in the sidewall. Vibrations or a change in the dynamic properties of the tire could also be an indicator of aging problems, and the tire should be replaced immediately. 
It's too bad that tires don't have a "sell by" date, like cartons of milk. Since there's no consensus from government or industry sources, we'll just say that if your tire has plenty of tread left but is nearing the five-year mark, it's time to get it inspected for signs of aging and look into investing in a replacement.