by Bill C. -
I recently noticed some cracking on the sidewalls of nearly new looking tires on my pickup. What about your VW? Vintage tires or not, we all need to know this about tire shelf life; especially regarding how to read your tire codes and when the warning flag should pop up. Tire materials decompose with time. Besides those side wall cracks, the tread can actually lose its bond and fly off.
Even though the US citizenry is largely uninformed on this, new tires should not be sold more than 6 years after the manufacturing date. The dealers know this, but don't always heed the requirement. You especially have to watch if buying USED tires!
For years, people have relied on a tire's tread depth to determine its condition. But old tires pose a safety hazard.
Cracks in the rubber begin to develop over time. They may appear on the surface and inside the tire as well. This cracking can eventually cause the steel belts in the tread to separate from the rest of the tire. Improper maintenance and heat accelerate the process. Tires that are rated for higher mileage have "anti-ozinant" chemical compounds built into the rubber that will slow the aging process, but nothing stops the effects of time on rubber.
Carmakers such as Nissan and Mercedes-Benz tell consumers to replace tires six years after their production date, regardless of tread life. Tire manufacturers such as Continental and Michelin say a tire can last up to 10 years, provided you get annual tire inspections after the fifth year.
Environmental conditions like exposure to sunlight and coastal climates can hasten the aging process. People who live in warm weather and coastal states should keep this in mind when deciding whether they should retire a tire.
So you need to know how to figure out the date of manufacture.
The Manufacturing Date Code is stamped on the backside (older tires) or front side. It will likely be within an "oval", preceded by an "x" or perhaps a series of letters. It is the last series of numbers in the code.
It will either be:
· - 3 digits if built in the 90s
· -4 digits if built in the 2000s
Decoding the code
·-3 digits - wwy - first 2 digits is the WEEK of the year. Last digit is the YEAR within the 90s (i.e. "5" represents "1995")
· -4 digits - wwyy- first 2 digits is the WEEK of the year. Last 2 digits is the YEAR within the 2000s (i.e. "05" represents "2005")
So, I check my pickup and find my magic code is "3305." So they were manufactured the 33rd week of 2005. Nice tread, but they're no "spring chicks!" So, right now they are approaching 9-years old. Think it might be time for some new shoes. Check it out. Don't buy OLD new tires!
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