This may have already been covered, if so my apologies.

Since the year 2000 all tire manufactures are required to have a DOT (Department Of Transportation) code stamped into their tire. The DOT code is used to identify when and where the tire was made. The last four digits are important to us, as they determine the week and year of the tire’s manufacture. Why is this important? Because tires now have a definitive means of determining their age. And, because of this things are changing with tire liabilities. Be aware, your tire’s age could be detrimental to your safety and liability!

Yes, liability!

If your tires are determined to be the cause of an accident and the tire's life expectancy has expired, you could be determined at fault. Further, some insurance companies are dismissing claims because of expired tire life and other companies may be planning to do the same soon (contact your insurance carrier for their standing on this). What this translates into; you could be responsible for all damages accrued by an accident for which it has been determined your tires were too old to be safe and at fault.

Not only to your own vehicle, but to other vehicles, properties and injuries as well.

This is especially relevant with our classic cars/hot rods as we often have more age on our tires than wear. The tire tread can show very little wear with the tire looking like new, yet it’s age could be out of date. How old is too old for a tire? This gets a little sticky; DOT says 6 years is the normal life expectancy for a tire, while some tire manufactures say as much as 10 years.

Which one do you think the insurance companies, attorneys and courts will choose.

Take a look at your tire’s side wall and find the DOT code, if your tire has no DOT code it is already older than 2000 and past it’s life expectancy. If it has a DOT code, use the last four digits, the first two of the four last digits are the week of manufacture, the last two are the year. Check the DOT code on all your tires. And, check the DOT code when you purchase new tires, they may have been sitting around longer than you think.

Only the DOT code determines the tire’s age, it makes no difference when they were purchased.