When choosing tires, Sharon Cowart, product marketing director for Michelin Americas Truck Tires, says that the first step is to determine what your goals are for your tire program.
“For over-the-road operations, it is a common goal to maximize fuel savings,” she begins. “For more localized operations the goals may be more focused on lowering the cost per mile. Additional goals may be to maximize the overall life of the tire as an asset, which looks at the value of the casing for retreadability.
“Once you have an idea of your overall goals,” she continues, “it makes selecting the right tire a smoother process as it guides you through it. Start by looking at the same tire size that you currently have on the equipment by wheel position, and then explore what options are available in that size to meet the specific conditions under which the equipment will operate. For example, this might entail specific load carrying requirements, weather conditions or environmental issues such as SmartWay-verified products or tires which operate well in snow conditions.”
Cowart recommends working with your OEM dealer to understand options on the model of truck or trailer you are looking at, and comparing those options with your goals.
“If you are purchasing used equipment, be sure to look at the tires currently on the equipment, including the condition,” she recommends. “Make sure the tread design is in line with your goals. This may be an area of negotiation when purchasing the equipment. Equipment plays a big role in determining the proper tire. If a truck is a 6×4 application the tire selection may be different than a 4×2 or 6×2 application due to the amount of torque being applied. Tire manufacturers may use different tread depths, compounds and tire design features depending on the targeted applications.”
Tire manufacturers normally indicate on their website which tires are best suited for the various applications.
It’s all about application
As with basically every aspect of your fleet, the most important thing to know before you spec tires is your application and needs. This will inform every aspect of the spec’ing process.
According to Gary Schroeder, director of Cooper’s truck and bus tire business, including the Roadmaster brand, service applications are typically broken down into three categories: long haul, regional haul and mixed service.
“Long haul tires are designed for on-highway use, while regional haul tires are designed for more urban-type deliveries that involve a higher amount of starting, stopping and turning. Mixed service tires are designed for extreme applications such as waste haul, dump truck or concrete mixers,” he notes.
“Selecting the right tire for each application and executing a proactive tire maintenance program is crucial to increase tire life and prevent unwanted downtime,” says Ron Greenleaf, region sales manager with GCR Tires and Service. “We strongly recommend that fleets work with a trusted tire professional to select the proper tire size, load-carrying capacity and speed capability suited to each application.”
According to Greenleaf, GCR first discusses with potential customers the type of carrier the fleet utilizes, the average miles traveled per year, and the number of trailers and trucks in the fleet.
“Performance expectations need to be realistic and take into consideration all aspects of the operations,” Michelin’s Cowart notes. “If a fleet runs both long-haul and regional applications, then the expectations must be different for each segment of the operation. Likewise, fleets with multiple locations in different regions may need to adjust their expectations for that zone. It would be unrealistic to have the same targets.”
“All fleets, even those in the same vocation, operate a little differently, so they will all have a different set of needs,” says Rick Phillips, vice president of sales for Triangle Tire USA. “Until you understand those needs it’s impossible to recommend a solution. This ‘discovery process’ could be lengthy and time-consuming, and it’s important not to rush it. Once the needs are identified, and agreed upon by the fleet, they are prioritized and an action plan is created.”
Value, not cost
The initial cost of the tire is not the only factor in the overall value that the tire will provide to your fleet. There are plenty of other factors that will contribute to the tire’s total cost of ownership (TCO), from performance to durability to retreadability.
“A replacement tire that offers the best value is not necessarily the one with the lowest price,” notes Michelin’s Cowart. “Select a tire that is best for your application needs while also offering good performance and durability that may meet multiple life needs for retreading. That’s the best measure of the overall cost of ownership and return on your tire investment.”
‘Fuel costs can represent the single highest non-payroll operating expense. Rolling resistance of the tire accounts for approximately a third of fuel costs. The lower the rolling resistance, the less fuel consumed. A 3% reduction in rolling resistance translates into a 1% fuel savings or an increase of .06 miles per gallon. Low rolling resistance tires can offer both performance and fuel savings.
“Tire selection should include maximum loads the fleet may be carrying under day-to-day operations,” she continues. “Every tire manufacturer publishes load and inflation charts for their tires. Tires are designed and optimized to carry a desired load at a specified pressure. Proper pressure for the maximum load being carried is very important. Under-inflation and over-inflation for the loads being carried will affect tire and casing life and performance.
Cowart goes on to say that fleets should always have a good written maintenance policy in place to specify the maintenance practices they want followed. This policy should be specific to their vehicles, equipment, geography, distance they travel, loads they carry, time on the road and other pertinent factors. It should also cover the specifics of new replacement tires entering their fleet as well as a retreading policy, she notes. A section of this maintenance policy should include scrap analysis.
Once the tire choice has been made, you can focus on maximizing performance based on operational and maintenance factors. Developing a regular tire maintenance program, as well as regular monitoring for proper tire inflation, routine tire rotation, irregular wear and tire casing integrity, is recommended. Maintaining proper inflation pressure in tires is the single most important factor in extending tire life.
Roadmaster recommends rotating tires when they are 50% worn, or even earlier if they show signs of irregular wear, Schroeder says. Changing the direction of rotation can also even out heel/toe wear on the shoulders of drive tires and erratic wear on the shoulders of trailer tires. Steer tires are normally rotated side-to-side, which changes the direction of rotation and helps even out wear. At a 3/32 to 4/32-in. difference in tread depth between the drive axle tires, a cross-rotation would be recommended to even out the wear and increase tire life before removal. Directional tires are the only tires that should not change the direction of rotation. Drivers of trucks with dual drive axles perform a tire rotation if the wear gets to 3/32nds of an inch to 4/32nds of an inch difference from axle to axle. If irregular wear is noticed, a cause must be determined, and the situation resolved.
“To properly maintain tire assets and maximize their life,” GCR’s Greenleaf says, “we recommend fleet operators: Inspect tires for damage such as cuts, cracks, bulges and penetrations; monitor and set proper cold inflation pressures [inflation pressure of tires before driven]; confirm the tire’s maximum recommended speed, which may be lower than posted speed limits; and closely monitor tread depths to ensure the tire is not wearing through the tread package.”
“Periodic fleet inspections are a great way to see what is going on with truck tires,” says Juan Britos, senior technical services specialist at Hankook Tire. “These visual inspections can provide many clues related to how the tires are responding to the application. Cost per mile is a simple calculation we use with our fleets to compare tires across the same fleet; it can assist in determining what tire is yielding the most miles at the lowest price.”
Retreading is another way to extract more value from your tires than they initially offer. The more times you can retread the casing, the more value the tire has to your fleet’s operating costs.
“To get the most out of your tires, it’s important to find a tire that provides long miles to removal, as well as one that takes into account the casing quality and belt package,” Cooper’s Schroeder says. “The casing quality will tell you a great deal about the tire—how it will hold up and the value the tire has for its second and third life in retreading. All Roadmaster tires are engineered for retreadability and are backed with a strong warranty of two retreads within six years.”
“Retreading definitely lowers the fleet’s overall operating cost,” Triangle Tire’s Phillips adds. “Each fleet will generate casings at a different rate so they will need to plan new tire purchases accordingly.”
“Retreads provide fleet operators with a lower cost per mile solution over time, especially when fleets achieve multiple retreads per casing,” says Sanjay Nayakwadi, director of product strategy for Bridgestone Americas tire operations. “To maximize the number of retreads per tire, we recommend fleets place the first and potentially second retread in the faster wearing drive position and move to the slower-wearing trailer positions with subsequent retreads. We have observed that most premium commercial tires can be safely retreaded more than once with proper maintenance and inspection. Bridgestone tires can be retreaded multiple times and are backed by our enhanced casing limited warranty.”
Another good way to add to the overall cost of tire ownership is to not fall victim to Compliance, Safety, Accountability (CSA) citations.
“There is no magic formula to avoid CSA citations,” Triangle Tire’s Phillips says. “Compliance can only be achieved by regular inspections. The fleet’s level of commitment to its maintenance program is usually proportional to the level of compliance they achieve. A good preventative maintenance program is an investment. Not only does it lower the cost per mile, but it also helps avoid penalties and fines from noncompliance.”
Cooper’s Schroeder agrees: “Tires play a major role in complying with the CSA program because of their importance to the overall operation and safety of vehicles. Violations cost money and downtime, so it is important for owners to employ routine tire maintenance procedures to ensure tires are in good working order and to help avoid CSA violations. Not having enough tread depth is among the most common CSA penalties. Steer tires must have 4/32 in. of tread depth and other tires must have 2/32 in. You can ensure there is adequate tread depth for the wheel position by using a tread depth gauge.
“Making a conscious, proactive effort to focus on tire maintenance and replacement is important to the performance and safety of tires,” he continues. “Properly maintained, serviced and inflated tires last longer. Fleets should also consider using tire pressure monitoring systems (TPMS) on trucks and continuous tire inflation systems (CTIS) on trailers to simplify and improve tire pressure maintenance. Improved tire pressure maintenance will not only help prevent CSA violations, but will also help improve fuel economy and tire wear.”
The fleet perspective
Peter Nativo, vice president of fleet solutions with Oakley Transport, offers his perspective on tracking tire replacement.
“I track tire replacement by vehicle and mileage to get mileage reports and cost per mile,” Nativo says. “We have an inspection process at our terminal here in Florida and every outbound and inbound trailer has the air pressure and tread depth checked daily. We also have tire vendors throughout our system that perform quarterly inspections at predetermined locations and provide us with reports on their findings. We have an in-house tire alignment machine and we align every truck in the fleet when it’s new, once a year thereafter and at every front steering tire replacement—even on the road when possible. In addition, we purchased the alignment machine ($25,000) and created our alignment policy after reviewing years of documentation and information on tire wear, pressure testing and irregular tread depth.”