Buying A Used Car Soon? Be Concerned about the Tires!

Planning on buying a used car in the near future?  Just because a tire looks OK does not mean it is safe to use. Modern tires are highly engineered products that must withstand the weight of a car plus the forces from braking and turning while providing a comfortable ride and increased gas mileage. Even without exposure to heat and friction from the road, certain tire compounds like natural and synthetic rubbers decompose over time.

Tire manufacturers must provide the date on which the tire was manufactured, but not the date by after which the tire should not be used. To make matters worse, the  date is provided using a cryptic code that most consumers cannot easily read.  Some used car dealers place the tire information on the  inside wall of the tire making it impossible to even see.

How do you know if the tires on the car or turck you might buy are too old? Experts warn that tires more than six years old can fail catastrophically. Also exposure to heat, (such as we have here in Arizona), sunlight, and even ozone can shorten the lifespan of a tire, even if there is plenty of tread remaining. Spare tires are particularly at risk, because they can sit in the trunk of a car for years without replacement.  If your tires are in otherwise good condition, consumer safety analysts recommend changing your tires before they reach six years of age.

Although tire manufacturers are required to stamp the date of manufacture for each tire, it might not be immediately obvious where to locate such information on the tire sidewall. Each tire has a required Department of Transportation (DOT) number imprinted on at least one of its sidewalls. That number begins with the letters “DOT” and may contain up to 12 additional numbers and letters. The first and last digits are the most important.

  • The first two letters or numbers identify the manufacturer of the tires.
  • Prior to the year 2000, the last 3 digits of a DOT number represented the week (2 digits) and the year (1 digit) of production. So if the last three digits are 408, the tire was produced in the 40th week of the 8th year of the decade. There was no universal identifier that confirmed which decade in which the tire was manufactured (however, tires produced in the 1990s may have a small triangle following the Tire Identification Number).
  • Tires produced after January 1, 2000, have a 4-digit date code at the end of the DOT number. The first 2 digits represent the week of production and the last 2 digits represent the last 2 digits of the year of production. So, 5107 indicates the tire was produced in the 51st week of the year 2007.

Tires are the only part of your car connecting you to the road. Even the most expensive sports cars cannot outmaneuver a tire blowout. Make sure you take adequate precautions to keep you and your loved ones safe by checking the condition of your tires regularly and replacing them before they are too old.