WINDSOR, Ont. – When fuel prices began skyrocketing in the mid-2000s, it forced truck fleets to re-evaluate every aspect of how they consume the precious resource. Surcharges were put in place, drivers were trained on efficient driving and fuel-saving devices like auxiliary power units and trailer side fairings suddenly became mainstream. Now with tire prices charting a similar course as the result of rising raw materials costs, many fleets would do well simply to convince drivers to check inflation pressures with a tire gauge. Yet tires continue to be one of the more overlooked components when performing routine maintenance on a tractor-trailer unit.

One way to manage tire expenses is to reduce the costs of on-road failures – and that begins with trying to prevent them in the first place.

Pressure points
Even today, many drivers judge the health of their tires and attempt to determine their inflation pressures with nothing more than a thump of a hammer. The ‘thump method’ is even taught at many driving schools. Yet, any tire expert will tell you that the only way to accurately measure inflation pressures is to use a tire gauge.

“Inflation is always the number one important factor in tire maintenance,” said Brian Rennie, director of sales engineering, Bridgestone Canada. “It’s been that way forever and I’m sure it’ll be that way going forward. Thumping the tire with a club doesn’t do the job. You need to measure the actual inflation pressure.”

To prove this point, Goodyear once assembled a collection of over-, under- and properly-inflated tires at a trade show and invited truckers to identify them based on the age-old thump method.

“The results weren’t too sterling,” recalled Mark Pillow, director of business solutions with Goodyear Commercial Tire Systems. Thumping tires to determine their inflation pressures may be the most archaic practice in widespread use today, yet few fleets have found a way to impress upon their drivers the importance of measuring inflation pressures using a tire gauge.
“I don’t know how we as an industry overcome that,” Pillow said. “Some things die hard.”

Even Morrice Transportation, which runs a very effective tire program, struggles to get its drivers to use tire gauges.

“We try,” said Jeff Reaume, manager of maintenance and properties with the Windsor, Ont.-based fleet. “Most of them are pretty well still whacking tires unfortunately. Our highway drivers are much more diligent than our city drivers are.”

Bridgestone’s Rennie said at minimum, inflation pressures should measured with a tire gauge every two weeks. At Morrice Transportation, whenever a mechanic has a few minutes to spare, he checks the tire pressures on any equipment that’s parked in the yard. Long-haul drivers should at least be accurately measuring inflation pressures before setting out on a long-distance trip.

“If you did nothing but keep the air at the proper inflation on a consistent basis, it would decrease your over-the-road tire failures dramatically,” Pillow said.

Match them up
When tire failures do occur on the road, it’s important to match both tires on a dual assembly as closely as possible. This is becoming easier as tire suppliers offer more advanced emergency roadside service programs that can quickly examine the inventories of nearby tire dealers and dispatch the provider that has the ideal tire in stock.

In a perfect world, fleets should replace a failed tire with the same make and design as the tire that it will be paired with.

“The recommendation would be to match them as closely as possible at the beginning and if it’s not perfectly matched, then make the switch when you get back to the shop,” advised Bridgestone’s Rennie.

Large fleets often stock a variety of used tires at various stages of wear, so they can match up tires with similar tread depths. Tire manufacturers recommend two tires on a set of duals have no more than a quarter-inch difference in diameter, or 1/8th of an inch (4/32nds) variance in tread wear. Otherwise, the larger diameter tire will carry more of the load, possibly shortening its life while the smaller diameter tire is subject to irregular wear.

If a failure occurs on the side of the road and the surviving tire on a set of duals is worn, it’s best to replace both tires at the same time, Pillow suggested. Otherwise, be sure to notify the maintenance manager when the truck returns to the shop, so the tires can be matched up then.

Rennie said many fleets will choose to purchase a standard tire when they suffer an on-road failure (say, a premium drive tire) and then remove it when the truck returns to the shop, place it in their inventory and replace it with a used tire with a tread depth within 1/8th of an inch of its mate. It’s a constant juggling act that can add life to your tires.

Collateral damage
Another concern when experiencing an on-road tire failure is the potential impact a blowout could have on the mate tire. In some cases, the rubber remnants from a blown tire will cause damage to the sidewalls of the adjacent tire on a set of duals or even to the trailer itself.

In the worst-case situation, this could weaken the sidewall of the surviving tire, causing a “zipper failure” in the shop. The sudden release of highly pressurized air as the tire zippers has been known to kill technicians who were tending to the tire.
Zippering can also be a byproduct of overloading a tire for any length of time. John Overing, business unit director, commercial products with Yokohama Tire Canada, suggested drivers resist the urge to “limp” back to the shop when they experience a tire failure.

“If there was a complete failure on one tire and the driver continued (to drive on it), it’s possible the second tire has run overloaded,” Overing said. Whenever a truck has been driven on a flat tire, Overing recommended having the mate inspected by a tire expert.

“The best practice is to remove the other tire from the wheel assembly and to inspect it to see if there is any indication of overloading,” he said. “If you don’t do that and you simply replace the tire that failed, there’s a possibility of failure on the other tire fairly soon after.”

Tire professionals will examine the inside of the tire for signs of “blueing” caused by excess heat and other indications of damage. Rennie said in many cases, the tire that suffered the initial damage could be repaired while the mate suffers irreparable harm from being overloaded while “limping” to a shop.

Ditching the spare
This time of year, many of us have made a New Year’s Resolution to lose the spare tire around our midsections. Many fleets have already shed the extra weight associated with carrying a spare tire underneath their trailer. The cradles are still there, but they’re now frequently vacant.

Improved reliability of both new tires and retreads coupled with better roadside service availability has enabled this trend. There are several benefits in leaving the spare tire in the shop. If you are running at full legal weights, the extra payload will be welcomed and even if you aren’t, pulling an extra tire and wheel assembly can cause increased fuel consumption.

Doing away with a spare tire could save nearly 200 lbs, which can at least partially offset the additional weight of all the emissions-busting equipment that’s been added to tractor chassis in recent years. And then there’s the cost of buying all those extra tires.

“We don’t carry them at all,” said Morrice Transportation’s Reaume. “At one time, we used to run them on a lot of our trailers. But I run 300 trailers. That’s 300x$400 that’s sitting there doing nothing. That’s a lot of overhead that’s been absorbed by no longer having to carry spares with us.”

When Morrice does suffer a tire failure on the road, it calls Goodyear’s fleetHQ program, which has a history of getting the equipment back up and running in short order, even when failures occur in rural areas.

Yokohama’s Overing also pointed out that theft can be an issue when carrying a spare tire. This may become a growing concern as tire prices increase. Anecdotally, you hear a lot more about fuel theft when diesel prices are high.

“You don’t want to be driving around with a brand new tire on a wheel with a $600-$700 value that’s really being held on by a chain that any bolt cutter could cut through,” Overing said.

In retreads we trust
Retreaded tires get a bad rap, especially from folks outside the industry who mistakenly believe every piece of scrap rubber on the side of the road is the result of a failed recap.

Even fleets that do use retreads often limit them to trailer positions on local equipment. However, using retreaded tires is one of the most obvious ways to drive down tire costs and it won’t necessarily increase roadside service calls. Manufacturers insist retreading procedures have vastly improved in recent years, with the use of high-tech imaging equipment, and retreaded tires are every bit as reliable as their brand new counterparts.

“The quality of retreads is very high,” said Frederic Ollendorff, segment product manager, Michelin Canada. “We can say that the failure rate on a retread should not be any higher than on a brand new tire, if properly maintained.”

Sadly, retreads rarely receive the same attention as new tires when it comes to routine maintenance. So while they may be every bit as well-built as new tires, their relative neglect means they are more likely to fail, which adds to the perception they’re less reliable than new tires, Bridgestone’s Rennie explained.

“The comparison is not fair,” he pointed out. “The retreads that fail are probably, on average, less maintained than a new tire. Retreads are more likely to be placed on the trailer and if you look at the maintenance of the vehicle, the trailer probably receives the least attention. So the retread has an unfair disadvantage of failure.”

Pity the poor retread. All things being equal, there’s no need to question the reliability of a well cared for retreaded tire. Perhaps most telling, Yokohama’s Overing said: “I think you’re as safe running retreaded tires as you are running a new tire and this comes from a company that doesn’t have its own retreading process.”