# Tire age



## ebackhus

What's the formula for decoding a tire's age? I learned it many many years ago but have forgotten since.


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## 95five-0

I normally don't care how old a tire is I just check for dry rot and to see if it passes the penny test.

The penny test says when you put a penny in the tread with Lincolns head down you should not be able to see the top of the head.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=51


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## Volt-Schwibe

an expired web page that was still in google's cache said:


> DOT number: Every tire has a DOT (Department of Transportation) registration number. All begin with letters DOT. The next two letters or numbers identify the plant at which the tire was produced and the last four digits indicate the week and year the tire was made. For example, 1305, means the tire was made in the 13th week of 2005. Age can affect tires. Never buy new tires more than two years old. The other numbers are marketing codes used at the manufacturer's discretion. This information is used to contact consumers if a tire defect requires a recall.


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## V0lt

Yeah, I had a friend whose '87 Cressida had its tire blow out on the highway, all because it was a full-sized spare that hadn't been used in twenty years. It had dry rot on the sidewall, and I told him one day after band practice "dude, your tire is going to blow out, and I'm going to laugh at you when it does."

He just said it would be fine- that that tire had been like that for twenty years. Obviously not, or he wouldn't have had a blowout with a car full of kids on the way to hooters.


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## crazijoe

Tire dressing and cleaners that contain petroleum products will accelerate "dry rot".


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## ebackhus

Cool, thanks again!


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