We've all seen those beer commercials that talk about a "born on" date, telling you when the product was brewed. The same principle applies to tires.
When buying new tires for your vehicle, it's important to check the side of the tire for its manufacture date, said Connecticut Consumer Protection Commissioner Jerry Farrell.
"My tires had 50,000 miles on them so I knew it was time for a change, but I asked the technician to take a look at them anyway," Farrell said, while shopping for tires at a Wallingford dealer. "During his inspection, he explained how the materials used in tires naturally age and are affected by temperature, storage conditions, maintenance, and weather, and how tires can gradually harden and lose elasticity, leading to tread separation, cracking, and tire failure." Many times these changes are not noticeable from the outside of the tire.
Sean Kane, founder and president of Safety Research & Strategies, Inc., a Massachusetts-based national research organization specializing in safety matters, notes the majority of vehicle manufacturer owners' manuals now recommend tire replacement at or around six years -- regardless of tread wear.
Deciphering the code
To help consumers identify the age of their tires, the U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) requires that Tire Identification Numbers be printed on the sidewall of each tire. These numbers must identify the manufacturing location, tire size and manufacturer's code, along with the week and year the tire was manufactured.
The sidewall also includes the maximum pressure for your tires. But that's not necessarily the best tire pressure for your car, and you shouldn't inflate your tires to the maximum level.
Instead, look for a sticker inside the driver's-side doorjamb or glove box, or check your owner's manual for the correct air pressure for the tires on your vehicle. You will improve gas mileage by keeping your tires inflated to the proper pressure. Under-inflated tires can reduce mileage at a rate of up to eight cents-per-gallon of gas.
"When looking for the manufacture date on the sidewall, look for the long series of letters and numbers starting with the letters DOT," Farrell said. The week and year the tire was produced is printed as the last four digits of this Tire Identification Number; the last two digits identify the year, and the two immediately before them identify the week of the year. For example, if the last four digits read 2209, the tire was made in the twenty-second week of 2009.
Tire tips
"When you shop, consider choosing the tire that offers the longest possible life," Farrell said. "And remember, the unused tires sitting in your garage or in your spare tire compartment need to be checked for age also."
He also recommends having your tires inspected by your mechanic during regular automobile maintenance and keeping them inflated according to the manufacturer's recommendations for longest life and safest use. Regular tire rotation and checking for uneven wear will save on tires and gas costs.
"Buy a tire gauge and check your car's tire pressure every month," Farrell concludes. "If your tires are low on air, you're wasting gas and money. The best time to check your tire pressure is when the tires are cool -- not right after a long drive. In hot weather, check the pressure during the coolest part of the day."
