If there’s one thing trucking publications like to harp on, it’s taking care of your tires so you can be sure you’re getting the most out of them. Hopefully, at one time or another one of these columns has brought about the inspiration to go have a look at those tires yourself. And, maybe, particularly in long-haul applications, you’ve noticed tires are wearing differently across the truck.
Cue Darth Vader’s “Nooooo” from Revenge of the Sith.
I’m just kidding – don’t fret. There’s a reason for that; the trouble is nailing down which reason to blame. Maybe it’s because you’re using the wrong tire for that truck’s application, or the right tire in the wrong position. It could also be because of ignored maintenance. In some cases, it could even be by design.
Tire position has a lot to do with it. As you take a walk around the truck, you’ll likely find tires in each position have worn differently. That’s because, generally speaking, the more open a tire’s tread design, the quicker it will wear, according to Triangle Tire’s Charles Luther.
“A tire designed for traction with an open ‘block type’ design will normally wear at a quicker pace per 32nd-inch than a straight ribbed tire that is most often used on a steer or trailer axle,” Luther says. “Also, a drive axle tire has, more often than not, a deeper tread depth than a steer or trailer axle tire. As the blocks wear down, the miles per 32nd-inch of rubber will increase as the blocks become more stable at lower tread depths.”
Different styles of tread patterns also wear differently. Take a look at the difference between closed-shoulder and open-shoulder drive tires for a good example of this, says Cooper Tire’s Phil Mosier, manager of commercial tire development.
“Open-shoulder drive tires are typically used in a more local service or on/off-road service because of the traction required for those operations. However, if this type of pattern is used on a long-haul tractor, it may have a propensity for irregular shoulder wear,” Mosier explains. “This is also seen in the difference between regional steer tires with a solid shoulder and long-haul steer tires with a decoupling rib in the shoulder. Because tires in long haul operations wear very slowly, there is more opportunity for irregular wear to happen. The decoupling rib allows the shoulder ribs to wear more evenly by keeping the tire’s footprint flat on the ground.”
Trent Schwenkfelder, president of Idaho-based Commercial Tire, which operates 45 locations and three Bandag retread facilities within Idaho, Utah, Eastern Oregon & Eastern Washington, says a truck’s steer tire wear has led to some customers questioning the quality of the tire.
“Deeper tread does not [always] equate to longer wear. The decoupling groove on a steer tire is designed to battle lateral forces as the tire is rolling and is designed to wear away,” Schwenkfelder says. “Wear at this point on a tire can sometimes create confusion and concern for our customers.”
Sometimes the cause of an odd wear pattern has a much simpler answer. Marco Rabe, Continental’s head of research and development for commercial vehicle tires in the Americas region, says if you spot improper tire wear, check the tire pressure.
“While everyone probably knows that tire inflation is important, many people still underestimate how large this effect can be,” Rabe says. “Tire inflation will change the tread pattern in the contact patch of the tire. In other words, a tire that is not properly inflated is also not making proper contact with the road, reducing its ability to perform as it was designed. It’s best to keep your tires inflated to the manufacturer’s recommended inflation pressure. This will optimize tire performance, as well as provide the best mileage and fuel efficiency.”