Contractors hate leaving money on the table at a bid letting. But how much money are you wasting by neglecting your tires or by neglecting to establish a tire management program?
The amount will vary, but more importantly your tire costs are one of the few variables you can control.
“Tires are probably your largest manageable cost.” says Guy Walenga, director of engineering, commercial products and technologies at Bridgestone. “A tire is not a commodity. It is a unique piece of equipment that has a long original life and can be refurbished and have an extended life through retreading.”
We asked some experts to point out where contractors and equipment managers fall short on their tire management programs and what they can do to improve their ROI on this significant chunk of their operating costs. Here’s what they had to say.
1. Low air pressure.
If you’ve heard it once, you’ve heard it a thousand times. Maintaining the correct air pressure is the single best thing you can do to increase the longevity of your tires.
“Air carries the load,” Walenga says. “The tire is just a sophisticated balloon to keep the air in there.” Under-inflation causes the tire to flex more, which causes heat, which causes the tire to break down sooner. A 22.5-inch tire will revolve about 500 times per mile, Walenga says. By design, the sidewalls deflect as the tire goes into and comes out of the footprint and that movement is what creates the heat. The lower the air pressure, the greater the flex and the more the tire heats up, he says.
Tires should be at their target pressures, cold, at the start of the day. Tires mounted in duals need to be at the same pressure and additionally not have a variance of more than 5 psi, cold, between them.
2. Off-center mounting
Good mechanics know you don’t tighten any series of bolts in linear fashion, but Johni Francis, global products manager for Titan Tires says he’s seen it many times – somebody changes a tire and torques all the lug nuts by going around in a circle instead of cross tightening.
“Then you have a wheel that’s off camber,” says Francis. “That plays havoc on the wear of the tire and transmits a lot of vibration to the machine itself.” When the tire isn’t properly mounted, the beads don’t seat completely on the flange, he says. “That will cut the tire’s life in half. You change the flex point of the tire on the sidewall. You get excess wear in the flange area and create extra heat in the shoulder as well.”
“There is a process for mounting and it’s not hard,” says Walenga. “You have to put tire lubricant on both beads of the tire and both bead seats. It has to be tire lubricant. Not diesel fuel, not dishwashing liquid. Then get the tire mounted on the rim and throw a little air in there, just enough to get the beads to close up, maybe 5 pounds. Then roll that tire into a cage and air it up to its service pressure from inside a cage.”
Most people think that’s it, says Walenga, but the next step is to inspect the tire. Look for what the industry calls the guide ring. This is a small concentric line, or two on the tire just above of the flange of the rim and that guide rib should appear equidistant from the rim all the way around the tire. If it does not look equal all around, you are seeing a variation of more than 1.5 mm or 2/32-inch, which is the maximum variance allowed. Sometimes one bead will seat properly and the other will get hung up resulting in an off-center tire and a guide ring that is not evenly spaced around the circumference of the rim. Check both sides of the tire for this concentric seating on the wheel.
“If it’s not concentric, air it down, relube the wheel and bead and try it again,” says Walenga. “If it still isn’t right, measure your wheel to make sure it’s concentric and if it is, then call your tire guy.”
Walenga also recommends that you use new valve stems, grommets and valve cores and torque them correctly. “You can buy these by the carton for nickels and dimes,” he says. “This is the stuff that keeps the air in that you’re spending a lot of time doing deep knee bends to maintain it.”
3. Bad alignment
Proper alignment is another factor in stretching the longevity of your tires. It’s best the check this periodically, say, every time you have a truck or vehicle in for PMs, and checking the alignment is not complicated or expensive, says Walenga. If you wait until you can see the wear in your tires you’ve likely already used up those tires prematurely and lost a percentage of their value.
4. No pressure monitoring
As of 2008, tire pressure monitoring systems have been required by law on all new passenger cars in the United States. Off-road equipment isn’t subject to the same laws but there are dozens of different factory installed and aftermarket systems at different prices available for these bigger tires. The Tire and Rim Association is pushing for mandatory TPMS in off road equipment says Francis.
The simplest TPMS simply tells an operator or driver when the tire pressure is out of spec. Other systems can monitor temperature. The most sophisticated systems use an RFID device that sends signals through a cellular service to a remote website.
“I can turn on my computer at home and see trucks running in Africa or anywhere else in the world,” says Francis. “If there is a problem we can phone the tire service overseas and tell them there is tire on a particular position on a specific truck that is running low.”
On big haul and mining trucks monitoring technology can provide metrics such as road gradient, weight distribution, road camber, turn radius, inflation pressure, temperatures and GPS, says Francis. All of these will help a fleet manager better pinpoint operation issues or side conditions that pose risks to tires, he says.
5. Lack of a program
Consistently applied, a tire maintenance and management program can reduce or eliminate many of the problems and oversights that lead to early tire failure.
Train and expect your drivers and operators to inspect their tires before every shift says Eric Matson, manager, global field solutions OTR, Goodyear Tire and Rubber Company. Check not just for air pressure, but tread depth, irregular wear, cuts or mismatched tires, he says.
Construction site analysis is another good habit to develop, says Matson. “Take a look at your site, and examine the roads leading in and out of it. Are these free of rocks and other debris that can damage tires? How is the site manicured? How steep are the surface inclines and declines? Is there standing water on your site or has the site been engineered so that water drains away from it?”
You can also profit from identifying the root causes of tire problems, says Francis. Start with a periodic tire scrap pile analysis and look for common signs of premature failure such as:
- Separations in the tire and uneven wear toward the shoulder often point to issues with overloading, underinflating or running the tire beyond its recommended Ton-Mile-Per-Hour (TMPH) rating.
- Over-inflation may be the culprit behind impact damage and uneven wear toward the center of the tire.
- Frequent tearing or chipping of the treads may indicate that the fleet manager should select a different tread compound on their tires.
Establishing this baseline of performance will help you recalibrate maintenance and operations practices and make better tire selection decisions in the future.
If you lack the manpower or expertise for some of these maintenance and tire management programs consider partnering with your tire dealer, says Walenga, “Maybe you’ll want the dealer to come out every Saturday and check air pressure, change flats, and inspect or repair tires to make sure everything is ready to roll Monday morning,” he says. Some dealers might charge for this service, Walenga says, but some might throw it in as a value added service to customers who buy a lot of tires.
6. Wrong tire for the job
Selecting the right tire for the job and site conditions is critical to maintaining a low cost-per-hour, Francis says. Examples:
- Cut-resistant compounds are a good choice for harsh settings with sharp, uneven terrain.
- Wear-resistant compounds work well for machines that frequently stop and start on hard surfaces.
- Heat-resistant compounds are recommended for long hauls at higher speeds.
- Tread depth is also a key factor in tire life, and a fleet manager may consider a deeper L-4 or L-5 tread if an E-3/L-3 isn’t working.
Choosing the correct tire not only reduces O&O costs, but also can drastically improve productivity, says Francis. It’s important to look at how tire choice impacts the bottom line – not just replacement costs.
7. Untrained drivers
Much of the care and maintenance you put into your fleet’s tires will be for naught if your drivers and operators run the equipment or trucks in a harsh or reckless manner. Many tire experts will tell you that the majority of off-road tires are run to destruction long before the tread wears out.
But a little bit of education can go a long way. Studies conducted by Technology Maintenance Council (a trucking industry group) show that driver variation alone can account for up to 35 percent difference in fuel economy, says Walenga. And if you can train drivers to improve fuel economy you can do likewise to reduce tire damage. “Driver habit is very important to fuel economy and tire life.” Walenga says.
Under certain conditions in mines and quarries a tire dealer may recommend traveling at lower speeds, running fewer cycles or carrying smaller loads, Francis says. Such a suggestion is often hard to swallow for fleet managers, however. In the end, the tire dealer can consult with the fleet manager to decide which provides a greater cost savings – increased tire life or increased production. Whatever is decided, make sure the operators practice what is preached, he says.
8. Exceeding TMPH
Make sure that your tires do not exceed their TMPH or work capability factor rating, says Matson. Every construction tire has a specific TMPH/WCF rating which dictates how much it can carry at a specific speed, he says.
You can exceed your truck or equipment’s TMPH rating by going too fast or carrying too much weight for the tires’ ratings. Your equipment OEM and tire dealer can help you calculate the numbers.