Maintaining trailer tires is one of the most challenging aspects of commercial fleet maintenance since trailers are frequently rotated or released in a route or during a delivery change.
With tires making up one of the largest costs of fleet equipment, we’ve asked industry experts for tips on extending the tread life of trailer tires – recommendations to help your clients get the most out of their investment.
Choose the Right Tire
Fleets should consider the application and job function when selecting tires for a vehicle, says Robert Palmer, Bridgestone Americas’ director of market sales engineering. Today’s tires are designed to provide maximum performance, but even the best tire in the wrong application will not deliver the intended results.
Palmer recommends confirming tires are of the correct size and load range to meet the gross axle weight rating. Some newer vehicles require 16 ply (load range H) to meet the steer axle ratings, he says. In addition, fleets need to choose a tire with the appropriate speed capability for the service conditions. Palmer also suggests fleets select the appropriate tire design to ensure they get the most life out of their tires. Typically, most of the major application categories (i.e. long haul service, regional haul service, local pickup and delivery service and on/off-highway service) have a tire for each wheel position. Providing fleets with the correct options tailored to their needs means asking good questions.
Implement Routine Checks
Establishing an effective tire policy is key to maintaining a fleet’s tires. Matthew Hanchana, senior manager of the sales technical department for Giti Tire Ltd., suggests fleets address four key elements that contribute to the extended life of any tire: air pressure; rotation; mechanical maintenance of the vehicle, and speed.
Mike Graber, Toyo Tire’s senior manager for product planning and technical services, says implementing daily visual checks is one simple way to extend tire life.
“A pre-trip visual inspection while checking air pressure with a calibrated gauge will ensure tires are properly set for the haul,” Graber says. “Periodic maintenance like alignments and tire rotation will reduce the likelihood of mechanical factors causing premature tire removal.”
While there are lots of different elements to maintenance programs, it all starts with a commitment by the fleet, says Rick Phillips, vice president of sales for Triangle Tire USA.
“The fleet must be committed to a solid maintenance program,” Phillips said.
Maintaining correct inflation pressure is one of the most important tire-care practices that a fleet or owner-operator can employ to help ensure long tire life, says Evan Perrow, senior product marketing manager at Goodyear Tire & Rubber Co.
Perrow recommends that fleets and owner-operators check tire inflation pressures at least once a week, using a calibrated tire gauge. Other tire manufacturers recommend keeping track daily.
Giti’s Hanchana says for every 10% of under inflation in the tires on a vehicle, a 1% reduction in fuel economy will occur. That may seem small, but when you multiply by tire positions, trucks in your fleet and miles run per year, the cost adds up.
Triangle’s Phillips said checking air pressure should be a two-step process. First, fleet owners or operators should ensure that the tire’s air pressure matches the load it will carry.
“There are a lot of fleets that simply put 100 psi in every tire and in more cases than not, that’s not the correct pressure,” Phillips said. “On a typical 18-wheel tractor-trailer rig carrying 80,000 pounds, most steer tires need 105 to 110 psi and most drive and trailer tires only need around 85 to 90 psi. At 100 psi, the steer tires are underinflated and drive and trailer tires are overinflated.”
Overinflation can result in irregular wear as well. An under-inflated tire, however, will flex more than it should, which could lead to damage to the casing, called casing fatigue, says Phillips. During casing fatigue, the steel cords in the sidewall of the tire become hot and eventually break, which could affect the retreadability of the tire and lead to tire failure.
Once the proper psi is determined, the second step in the process is to make sure it’s maintained. Without the proper amount of air in the chamber to maintain the tire’s profile, it will never perform as it was intended and the fleet will risk additional financial impact.
Graber of Toyo Tire recommends checking air pressure in the morning when tires are cold since pressure will increase as tires get warmer with use. Measuring while hot will give you an inconsistent reading.
“Set the cold pressure to the level found on the vehicle placard rather than the sidewall,” he says. “Operators should weigh their truck while loaded and set the pressures to the appropriate level to safely carry the load.”
Note that the proper inflation pressure could also be found in the vehicle owner’s manual, listed on the inside of a glovebox or center armrest compartment or on the vehicle’s fuel door.
What to Look For
While air pressure is the most important factor in the care and keeping of truck tires, other maintenance checks should be performed to ensure proper tire care.
Tire rotation and vehicle alignment are two maintenance checks that are key to extending tread life.
Periodical rotation of tires can prevent or reduce irregular wear and extend the life of the tires while contributing to a smoother more fuel-efficient performance, Giti’s Hanchana says.
If irregular tire wear is detected, a best practice is to rotate the tire, says Tom Clauer, manager of commercial and OTR product planning for Yokohama Tire Corp. The most common types of irregular tire wear include inner/outer rib wear, (steer axle, toe setting), cupping or scalloping (all axles are worn out) and heel-toe wear. Regular tire rotation maintenance can also help detect worn and inoperable parts. Some parts that often need to be replaced are shocks, kingpins, wheel bearings and other suspension parts.
“Look for anything that’s not normal. One-sided wear, punch wear, spot depression wear or irregular wear on the tread edges – these are all signs you have a problem,” says Triangle’s Phillips.
Alignment is associated with the entire aerodynamics of the trailer and can also impact fuel economy, Giti’s Hanchana says. A vehicle is aligned when its tires are traveling in the same direction and producing regular wear patterns. To detect if an alignment is needed on your trailer, check the tire wear.
Clauer says if there is inside wear on one side of the vehicle and outside wear on the other side, your trailer is in need of an alignment. A misalignment can lead to an increase of total drag on the vehicle.
Bridgestone’s Palmer also recommends fleets check how their vehicles are mounted. Improper mounting can lead to irregular wear and result in ride disturbance over time, he says.
Palmer says, in addition, fleets should clean wheels carefully and check for bent or dented flanges, rust build-up and dirt or damage that can make it difficult for the tire’s bead to seat properly. He also recommended lubricating both the wheel and tire bead with a high-quality, vegetable-oil-based lubricant to make mounting loads easier.
Other preventive measures can be taken while driving. Fleet owners and operators should advise drivers to be aware of their speed, braking and debris on the road.
Avoiding heavy acceleration and braking helps to extend tread life. Rolling resistance, the force resisting the motion when a tire rolls on the road, increases with speed, Hanchana says. For every increase in mph above 55 mph, there will be a 2% reduction in miles per gallon. A dramatic increase in speed – such as a rapid increase of 10 mph – will result in an increase of fuel consumption and reduce travel time by very little. If the tire had been retreaded, high speeds will also cause high thermal and mechanical fatigue of the casing and can lead to lower retreadability and potentially premature failure, Hanchana says.
Drivers should also check tires for debris from the road, which can get embedded in the tire. Checking the grooves of the tire helps so that a foreign object doesn’t get worked deeper into the tread.
Recommending a Tire Policy
You know how the saying goes: time is money and money is time. And you’ll save both by recommending an effective tire “checklist” and working with customers to set goals for the tread life of their fleet.
Hanchana recommends a few best practices for implementing a strong tire policy. He suggests establishing a benchmark to determine the percent of tires in a fleet that achieve run out. This can be determined by observing operating conditions of a fleet. When doing this, a maintenance checklist can be tailored to meet certain goals. In establishing recommended tire pressure for vehicles, Hanchana recommends utilizing scales axle weights. Another benchmark he suggests is setting a removal tread depth based on data gained through scrap tire analysis, which can help produce high retreadability for casings.
For example, if every tire in your pile has been run down to the last 2/32s of tread and had multiple retreads, consider that a win.
“You might be hard pressed to call a pile of scrap tires a hidden treasure, but that is exactly what it is,” Hanchana says. “There is a wealth of knowledge in that pile about equipment maintenance, driver habits and the types and brands of tires you’re running on.”