Ignore them at your peril. Not only are tires among the top three or four cost centers for most fleets, they are also in a position to influence CMS scores, fuel economy, driver satisfaction and overall fleet safety. Shouldn't that make tires one of your top maintenance priorities?
The Rubber Manufacturers Association sponsors National Tire Safety Week (May 24-30) as a way of raising awareness about the importance of keeping tires in good working condition. The initiative is generally aimed at the passenger car market, but commercial drivers and fleets can share in the festivities, too.
“National Tire Safety Week is an opportunity for the tire industry to focus its collective efforts to educate motorists about the importance of proper tire care,” says Dan Zielinski, senior vice president of the Rubber Manufacturers Association. “Regular tire maintenance is critical to promoting a safe driving experience, optimizing fuel efficiency and maximizing tire tread life.”
Research by the American Trucking Associations’ Technology & Maintenance Council (TMC) has shown that tire underinflation by as little as 10% can result in a 1.5% drop in fuel economy, and underinflation by 20% results in a 30% reduction in tire life.
On top of that, we know from various government and industry studies that tire inflation maintenance is not great across the industry. If you're looking for a good excuse to send out a reminder to drivers and technicians about tire inflation maintenance, National Tire Safety Week is just the ticket.
“Simply put, safe and efficient trucks run on properly maintained and regularly inspected tires,” said Jon Intagliata, product manager for Tire Pressure Monitoring Systems (TPMS) at Bendix. “Tire performance and longevity are directly related to proper tire pressure, as are other fleet concerns such as fuel economy and maintenance costs.”
Here's a quick Top 5 list of basic and easy to perform tire checks that will go far towards improving tire life, fuel efficiency and safety.
1) Inflation — Pressure Checks
Drivers and technicians should follow fleet guidelines when inflating tires to the recommended pressure. Pressure should be based on the minimum pressure for the maximum load carried by the tire. Many fleets choose to inflate drive and trailer tires to 100 psi for a number of reasons, but that number is not universal. Check with the fleet for the desired inflation pressure before making any adjustments. Steer tire pressure can vary as well, from 100 psi and up to 120 psi in some cases.
Always check inflation pressure when the tire is cold, that is, before the vehicle is driven any distance. Heat generated during normal operation can raise internal pressure by as much as 10 psi. Checking a hot tire can give a false reading. And changes in ambient temperatures can cause pressure fluctuations as well.
"A tire with an initial cold inflation pressure of 100 psi at 60 degrees Fahrenheit ambient temperature will experience a two psi change for every 10-degree Fahrenheit change in ambient temperature," notes Donn Kramer, director of product marketing innovation, Goodyear Commercial Tire Systems. "Fleets operating at 66 miles per hour to 70 miles per hour should increase their tires' cold inflation pressure by 5 psi."
2) Inflation — Balance across duals
When we talk about matching two tires in a dual arrangement, diameter is critical to avoid premature wear of the taller of the two tires. Matched inflation pressure across the two tires is equally important.
The risk there, according to Matt Wilson, controls business unit manager at Hendrickson, is with unequal loading across the tires.
"The harder of the two does most of the heavy lifting, while the soft tire flexes its way to an early grave," says Wilson. "You end up damaging two tires because of a single problem. Equalizing the pressure across duals as well as maintaining optimum pressure by bleeding off excess pressure due to changes in ambient temperature or operational temperature helps prolong tread and casing life."
3) Inflation — ATIS & TPMS
Automatic tire inflation systems have been on the market more than a decade now, and tire pressure monitoring systems nearly as long. Both bring proven ROI to the table, and both eliminate much of the drudgery associated with maintaining optimum tire pressure -- and saving fuel.
According to a 2010 Department of Transportation field test of ATIS and TMPS systems, such technology contributed to improved fuel efficiency in the test fleets.
When presenting his findings at Technology & Maintenance Council of The American Trucking Associations Annual Meeting and Transportation Technology in February 2012, Chris Flanigan of FMCSA's Office of Analysis, Research and Technology noted the fleets using the ATIS systems and the TPMS systems both showed a 1.4% reduction in fuel consumption.
"That DOT study put any concerns to rest," observes John Morgan, product manager for Meritor Tire Inflation Systems. "The final bit of proof is that the fleets in the trial are still using the systems, and have equipped more vehicles in their fleets since the study wrapped up in 2010."
While ATIS systems can reinflate trailer tires only (for the time being), TPMS systems, with some help from drivers, provide the opportunity to manage air pressure at every wheel position.
"When we first install a TPMS system on a fleet, they can't believe what they see," says Jim Samocki, general manager at Doran. "Tire pressures are usually all over the map. That's when the impact of improper inflation starts to sink in. They're thinking of tire wear and damage, of course, but fuel economy is never far behind."
Of course, getting tire pressures reined in is just beginning of the good news. It's known that most tire blowouts are the results of operating while vastly under-inflated. The resulting heat destroys the compounds that bind the tire together and sooner rather than later the tire will come apart. The resulting downtime can be crippling.
"Roadside downtime has become a much larger interest to truck fleets for several reasons. Expense is first -- both the cost of the downtime and the cost of the repair, which can go as high as $900 to $1200," says Phil Zaroor, president of Advantage PressurePro. "And not making a dock time means more than just lost time, it could cause a loss of customer confidence."
It's easy to build a business case for such technologies, and their ROI is now well proven.
4) Cuts and Damage
Tires suffer all sorts of indignities, from flat spotting to curb damage. A quick visual inspection can reveal damage that could prove mission critical at some later point, that's if a DOT inspector doesn't see it first. Trucks can be put out of service depending on the severity of the damage. In any case, it's better to plan a tire repair or replacement than have one fail at an inopportune moment. Drivers are the front line inspectors in this case and they should be goaded or encouraged to perform these inspections regularly.
5) Irregular Wear
Like canaries in coal mines, tires can be the bearers of bad news. Irregular wear on a tire is not an indication of a bad tire rather it's a symptom of some other mechanical problem with the truck. Caught early, before the problem has a chance to ruin the tire, most tires can be saved once the wear becomes obvious. Early detection is the key -- along with fixing the source of the wear.
Drivers and technicians should be taught to identify the signs of irregular wear and encouraged to report it.
National Tire Safety Week comes just as summer gets under way, which exposes tire to additional stress from heat. Take a few minutes to encourage drivers and technicians to take the necessary steps that will improve tires life and probably fuel economy too. Nobody likes tire maintenance, but it's critical to safe and profitable operation.