Are My Old Tires Too Dangerous

By Brian Hogan

Leesburg, Virginia — Determining the age of your tires is crucial to your safety, the safety of your loved ones, and the drives around you. If you are driving with a tire that’s 5 years old or older, you could be putting a lot of people in danger. As tires age they tend to dry rot, from the inside out. That’s why it’s important to remember — just eyeing your tires at the surface may only tell half the story. This is a good enough reason why you should stay away from used tires also. Remember that tires are mainly comprised of rubber components, which means they will naturally age over the course of time, even if they have hardly been used at all.

Recently, investigations into the actual cause of the car accident that led to the demise of the Fast and Furious Star Paul Walker revealed that the car (Porsche Carrera GT) he was riding had 9 year old tires. California Highway 
Patrol said that the age of the tires’ might have compromised the car’s handling and drivability characteristics.

This basically means that just because the tires on your car have good tread, does not necessarily mean that they are safe on the road. More recent research studies have revealed that tires become unsafe as they age, even if they have never touched asphalt (this applies to “new” tires and spare tires which have never been used, but they’re old). This is because tires just like other rubber products, do have limited lifespan. Over time, the tire’s internal structures degrade, reducing the adhesion between belts, which consequently facilitates tread separation. The internal degradation happens regardless of the tread wear and use. This internal degradation is invisible and can’t be easily discerned without proper testing.

How Long Can a Tire Be Used?
If you happen to ask tire manufacturers, rubber manufacturers and auto manufacturers, what is the average lifespan of tires? These organizations will give you differing opinions. The NHTSA (abbreviation for, National Highway Traffic Safety Administration) does not have specific recommendations and defers to the particular manufacturer’s specifications. With that said, some auto manufacturers like Mercedes-Benz and Nissan recommend auto buyers to change their tires every 6 years regardless of the tread. Some tire manufacturers like Michelin say that a tire can last up to about 10 years so long as there are annual tire inspections after the 5th year. While Rubber Manufacturers’ Association says that there’s no clear way of putting a date 
on when tires expire because there are various factors like conditions of use, heat and storage which can dramatically reduce the overall lifespan of a tire.

So, what are the determining factors that will decrease my tire’s lifespan?

Heat — Tires tend to age much faster in warm climates as compared to the colder climates. Oxidation of rubber generally occurs faster under the high heat than in low heat. NHTSA has actually confirmed that a tire will age much faster in warmer climates. In essence, the heat increases both the reactivity and permeability of oxygen, which makes it easier for the oxygen to get through the tire’s inner liner and much easier for it to react with rubber that’s inside the tire. Therefore, those who reside in areas with warm climates should always keep this in mind when determining when to replace a tire.

Storage — Tires which are used less, are usually more vulnerable to the aging effects. This is because when a tire is driven, the flexing motion and pressure circulate internal oils through the tire’s rubber. These oils lubricate the internal rubber, which in turn keep it from stiffening and drying. Therefore, any tire which sits in a shop or garage unused for a long period of time will age faster as compared to the tire that’s on a frequently used car. With that said, you should note that if a tire has been mounted on the wheel, it’s considered to be “in service”, which means you should treat it as if it was already mounted on a car. A tire that isn’t mounted on the wheel will age much slower.

Conditions of Use — The way tires are treated when in use, offers a more accurate assessment on exactly how to determine how long the tires will last. If you drive your vehicle like a race car, your tires will age faster. Abuse of tires can include but not limited to; regularly driving on highways, running into curbs, among others. If you are ever in doubt about your tire’s safety, you should have them inspected right away by an expert tire specialist.

How To Determine the Age of a Tire?
Every tire comes stamped with a DOT (abbreviation for, Department of Transportation) code on the sidewall which reveals the year and the week the tire got manufactured. Typically the code has 11 to 14 digits, with the last 4 digits indicating the week and year that particular tire was manufactured. Tires which were manufactured after the year 2000 have a 4 digit DOT code; the 1st two digits of this code show week the tire was made, while the last 2 digits signify the year.

If replacing your tires is becoming a costly purchase every few years — we recommend regularly maintaining your tires to extend their life. With proper tire maintenance guidelines your tires can last up to 10 years.

Hogan & Sons Tire and Auto | Author: Brian Hogan| Copyright Sept. 2017