May 27, 2011 -- Before you get behind the wheel this Memorial Day weekend, take a minute to answer one question that is crucial to your safety and the safety of your passengers: How old are your tires?.
Old and unsafe tires are one of the leading causes of traffic accidents. Most drivers know that they should watch for excessive tread wear on their tires, but they're unaware that the age of the tire itself is also a risk factor.
Unscrupulous dealers sometimes sell consumers tires that look new but that have been sitting on a tire rack for years, and drivers who don't use a particular vehicle very often may think that minimal wear on its tires means they can delay purchasing new tires.
In fact, as all tires age they become more prone to losing their tread suddenly and causing an accident. According to the National Highway Traffic Safety Administration (NHTSA), when tires are older than six years, the chances of a sudden "tread separation" start to climb. Car companies and tire companies have sent bulletins to dealers saying that tires older than six to ten years should be replaced.
Fortunately, you don't have to depend on a professional to determine the age of your tires. The answer is right in front of you, written on the side of the tire itself.
Every tire has a Tire Identification Number -- a serial number -- inscribed on its sidewall. On tires manufactured after 2006, the number is written on the sidewall that faces out and is easily visible. On tires manufactured in 2006 and earlier, the number is inscribed on the inside sidewall, meaning that you would have to crawl under your car to read the digits.
The identification number starts with a serial number but then ends with a four digit batch code. Those four numbers tell you the age of the tire. The first two numbers are the week of the year in which the tire was made; the last two numbers are the year. A tire made in the 47th week of 2008 – meaning November 2008 – would have a serial number ending in 4708.
If the tire's number ends in only three digits, that means it was manufactured prior to 2000. A tire made in the 47th week of 1998 would end in 478. A tire with only three digits at the end of its Tire Identification Number is a tire that should immediately be replaced.