Time to Re-Tire Your Truck's Spare Tire(Lea en español)
One of our team members bought a used 2004 Ford F-150 Super Cab 4WD pickup. While preparing his truck for a Canadian vacation during the summer of 2014, he dropped the spare tire from under the truck bed to set its inflation pressure and check its condition. When he did, he saw that the full-size, Original Equipment BFGoodrich Rugged Terrain T/A spare tire had never been used, nor had it ever been replaced.
Installed on Ford's assembly line in 2004, the subsequent ten years of exposure to spring's rain, summer's heat and winter's sub-freezing cold, snow and salt had taken its toll. The other contributor to the spare tire's condition was ten years of inactivity. Once mounted, inflated and stored under the truck bed, extended inactivity actually causes tires to degrade quicker than if they experience frequent and continued use.
Even though never used, ten years of exposure and inactivity resulted in cracking in the base of the spare tire's tread grooves that confirmed replacement was long overdue.
The combined result of exposure and inactivity was the rubber had cracked in the base of the tread grooves around the tire. It could no longer be counted on, even in an emergency.
While it wasn't a surprise to discover the Original Equipment spare tire was still there, it was time for a new spare tire.
BFGoodrich has issued a Technical Bulletin covering Service Life for Passenger Car and Light Truck Tires including Spare Tires that recommends:
"While most tires will need replacement before they achieve 10 years, it is recommended that any tires in service 10 years or more from the date of manufacture, including spare tires, be replaced with new tires as a simple precaution even if such tires appear serviceable and even if they have not reached the legal wear limit.
For tires that were on an original equipment vehicle (i.e., acquired by the consumer on a new vehicle), follow the vehicle manufacturer's tire replacement recommendations, when specified (but not to exceed 10 years)."
The article on Ford's website providing tire safety and maintenance tips advises:
"If a tire is more than 6 years old, it is generally in need of replacement. Tires degrade over time, even when they are not being used. Heat caused by hot climates or frequent high loading conditions can accelerate the aging process. You should replace the spare tire when you replace the other road tires due to the aging of the spare tire."
While a spare tire may still have a new tread, it's an old tire.
Utilizing the Spare Tire
If a truck features the same tire and wheel combination as its spare, they should be included in the vehicle's tire rotations beginning with the first one. This will allow the owner to secure the spare tire's value and will prevent it from eventually aging out before ever being used.
Adding a fifth tire to the rotation pattern will also increase the longevity of the other four tires on the vehicle, as well as maintain equivalent tread depth on all five tires. This allows the spare to be put into service without the concern of different tread depths damaging the vehicle's four-wheel/all-wheel drive system.
Then when all five tires have worn out, they can be replaced at the same time. Doing so offers greater flexibility in selecting the next set of tires since all five tires will match in type, dimensions, tread design and wear.
If the truck features a matching spare tire mounted on a non-matching steel wheel (as in this case), it will require dismounting and mounting the spare and one additional tire to integrate the spare into the rotation pattern. While the value recovered by integrating the spare into the rotation may be offset by increased labor costs, the overall advantage is that it will increase the life of the five tires and maintain the spare at an equivalent tread depth.