“Every fleet needs to have a tire maintenance program. That program needs to be written down, well-communicated and followed,” says Jones. “Even if you outsource your maintenance to your local tire dealer, don’t take a hands-off approach. You need to make sure your dealer is doing it properly. By having a good tire maintenance program, you can minimize road calls and downtime associated with tire failures. You can also save money by using the casings multiple times rather than destroying them in their first lives.”
Regardless of tire brand or position, or fleet size, monitoring air pressure needs to be at the top of anyone’s maintenance list.
“Air pressure is so critical,” says Decker. “As tire manufacturers, we may sound like broken records, or that we don’t know what else to say. But at the end of the day, air pressure has the greatest impact on how long a tire will last — not only through the first life, but every life after that.”
Air pressure needs to be checked on a regular basis, ideally at the beginning of each work day when the tires are cold. Use a calibrated tire gauge to get an accurate reading.
The consequences of running on under-inflated tires can be costly in terms of irregular wear that shortens tire life, adds to tire costs and causes outright tire failures. “Running 20% under inflated costs you 16% in removal miles,” says Cohn, explaining that you’ll get 16% fewer miles.
Those lost miles are due in large part to the extra heat generated in an under-inflated tire. It flexes more than it’s designed to, creating excessive heat which breaks down the bond between the rubber and the steel. If severe enough, it can ultimately break open the air chamber. It also adversely affects your ability to retread the casing.
Consider an 11R22.5 tire, suggests Walenga. “Every cable in that tire will flex from rest to deflection, then rest again more than 500 times for every mile,” he says. “At 60 mph on the highway, you can see how that excessive deflection can destroy a tire. Heat is definitely the enemy. Proper air pressure for the load keeps the tire performing within the design parameters and keeps heat at bay.”
An under-inflated tire running as a dual can also wreak havoc on wear. Even with an inflation difference of just 5 psi, the distance a tire travels in one circumference (defined as rolling circumference) will vary by as much as 5/16th of an inch. When those tires are bolted together in a dual position, the two tires traveling at different rolling circumferences will cause uneven wear. “The tire with the larger circumference will roll along and the tire with the shorter circumference will have to skip to keep up, because with every revolution, it’s falling behind,” says Decker.
“It might not destroy the tire,” adds Walenga. “But it will certainly use it up faster. And it can, over a period of time, degrade the casing so you don’t get as many retreads as you could if air pressure was properly maintained.”
That irregular wear can also add to tire costs indirectly, notes Decker. “Every time someone touches a tire, it adds to the cost,” he says. “When a tire has to be rotated around the truck to give you the best tire wear, every time you take that tire off the truck, your labor costs go up.”
With all the dire consequences of running under inflated, you might be tempted to over inflate the tires to compensate for any air leakage. “But don’t simply pump air into the tire,” says Decker. “Find the inflation pressure that works for your needs and stay as close to that inflation pressure as possible. A comprehensive tire program centered around inflation saves money in the long run. That’s true for an owner/operator who may have one truck or a fleet with a hundred.”
Catch injuries early
Other maintenance items to add to your checklist include routine checks for debris. “It’s important to keep the tires clean,” says Jones. “Debris can get caught in the tread and sidewall of the tire and can cause it to deteriorate. Pay special attention to duals. Debris and rocks can get lodged between the tires and cause them to fail.”
“It’s natural in an off-road environment to pick up nails, screws, etc.,” adds Decker. “But the earlier you can catch an injury, the more successful the repair will be.”