How Old Are Your Tires?

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This article is not exclusive to antique and collector cars but relates to all of the vehicles we drive. An ABC 20/20 news article described how tires that looked perfectly serviceable actually failed catastrophically. It was reported that useable tire life is only about six or seven years.  Antique and collector cars tend to spend more time in the garage so the tires don’t wear out as much as they “time out”.
When you purchase tires, you need to know they haven't been sitting in a warehouse for several years.  It is important to be able to decipher the date of manufacture code.  This code is located on the sidewall near the rim.  Note, it may be on the inside of the tire depending on how it was mounted.



There are two different dating methods. According to information provided by The Tire Rack:

Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year. (for example DOT U2LL LMLR 5107 was made the 51st week of 2007.)

The Tire Identification Number for tires produced prior to 2000 was based on the assumption that tires would not be in service for ten years. While they were required to provide the same information as today’s tires, the week and year the tire was produced was contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year. (in this instance DOT EJ8J DFM 408 was made the 40th week of the 8th year of the decade.)

I read one account of a Porsche owner driving his fully restored ($100,000 plus) Speedster across a bridge when an old tire self-destructed.  The owner momentarily lost control of the car and it swerved into the side of the bridge causing considerable damage to the car.  Luckily, nobody was injured. 

Fresh tires are relatively cheap insurance.  How old are your tires?

Update - The following comments were provided by a local tire dealer.  He provided some insight into the 20/20 video.

1. The tire tread  shown on the side of the road were truck retreads - nothing to do with the issue.

2. The test vehicle that went out of control, when a tire failed, was an old Explorer.  The video is over 10 years old shown when the Ford/Firestone problem was in the news.  Fact.  Explorers produced before 2001 continue to roll over no matter what brand of tires are on them.  The issue then and today is that most failures are caused by tires that are in bad condition and or are underinflated.  We routinely see tires with less than 20 LBs of air in them.  When most vehicles experience a tire failure, the driver can safely pull over and stop.
3.  Where the tires are stored is more important than the date produced.  Tires kept outside in the sun age much faster than tires kept in stockrooms.
4.  Even though there are several agencies and vehicle manufacturers that recommend tires be removed after 6 years, no scientific study has shown that is an accurate date.  Our goal is to sell all tires before they are 3 years old.
5.  The statement that there is a secret "cryptic" code is a farce.  Every tire we sell has the DOT number listed on the invoice.  The last 4 numbers indicate the week and year the tire was produced.  Not rocket science!   If you purchase tires from any source that does not have the numbers on the invoice you might want to buy your tires somewhere else.