Its late spring and things are starting to heat up here in Phoenix. With the heat the strain on old tires becomes even greater. Every year almost like clockwork, when the temperature hits 100 degrees we see to trucks bringing in blown out tires and separated tires. Sometimes it is due to a nail that has caused the tire to be low on pressure and caused it to blow. But many times tire separations and resulting blow outs are due to the age of the tire causing the tread to separate (tire hernias).
Tire manufacturers vary as far as how many years they will cover tire separations under warranty. But a good rule of thumb would be that few if any cover them past 6 years of age. Why would they put an age limit? Well the truth is the way tires are made is through a layering process that relies and glues and bonding between the rubber and the radial belt of the tires and over time this bond is weakened and the rubber compound changes.
As the tires age in our hot and dry weather this makes the rubber dry out and become brittle. The age also weakens the bond between the radials and the tread rubber. The end result is cracking that develops around the outer sidewall and between the tread itself. Eventually the cracks separate which can result in the tread coming off the rest of the tire, a bulge from middle layer separation, or a crack that causes air loss and failure of tire under load.
At C & R Tire we start recommending that tires are replaced when they are over 4 years old. Most of the time we can visually see the cracks developing on the sidewall or tread of the tire and give the customer some warning before total failure of the tire occurs. By 6 years old we cannot safely do a flat repair on the tire and we consider it critical to replace the tires as soon as possible.
How do you know how old your tires are? Every tire has a department of transportation (DOT) serial number which the last four digits are the week and year the tire was made. We check these serial numbers any time we see a tire showing signs of being older and keep our customers aware of tire age so they can avoid unwanted tire problems.
The best strategy to avoid tire failure is to have your tires checked often for tire pressure, tread depth and age. We at C & R Tire do free tire inspections where we check for objects in the tires, uneven tread wear and for age and separation problems. If you haven’t had your tires checked, or if you are not coming to our stores for regular maintenance, we invite you to stop by and let us check your tires for free. Together we can make Arizona roads a safer place by replacing our aging tires and keeping them properly maintained.