There are as many factors affecting overall tire cost as there are ways of measuring and tracking it. How you track tire costs might have more of an impact on the number than your actual maintenance practices. And some may ask, why do you need to know your lifetime tire cost?

This month, we offer two opposing views on tracking tire costs. One holds that life-cycle costing is a waste of money and effort, and that close enough is good enough most of the time. The other suggests that nearly all costs associated with tires should be accounted for and built into the cost structure.

Interestingly, holders of either view on tire costing come to a similar conclusion: “If you’re doing all the right things, the cost is going to be okay.”

“If you’re looking at the cycle of the individual tire, I don’t know that it matters,” says Darry Stuart, a former fleet maintenance director now offering maintenance consulting services under the DWS Fleet Management Services banner. “What really matters is the vehicle’s overall tire cost per mile.”

That, Stuart insists, can be averaged out over the life of the tire, and it will vary with the application and number of times it is repositioned and retreaded. For example, he suggests a drive tire in linehaul service should last about 250,000 miles on average. At that point, you take the tires off and retread them and put them back at a drive position where they’ll run another 200,000 miles. By the time the first retread is worn out, the original casing might be five or six years old, so you cap it again and move it to a trailer position where it runs about 50,000 miles a year (depending on the ratio of trailers per tractor) for another three years.

At that point the casing is eight or nine years old and probably too old, damaged or tired to be capped again, so it’s sold or scrapped. The overall cost for those tires could look something like this:

• Acquisition cost - $400

• First retread - $200

• Second retread - $150

• Total miles on the original casing - 600,000

• Overall cost is dollars divided by miles - $0.00125

That’s a pretty good number, but it’s only the cost of the rubber. If you add in the cost of maintaining that tire over its life the number will be higher, and that’s where your maintenance practices come into play.

“If you fail to maintain the tire, your costs will be higher,” Stuart notes.

The sad part is some of the tires (up to 60% of them in the real world) will be damaged in ways that are beyond your control, and that can wipe out all the time and effort you have put into maintaining that tire.

“How much energy and data are you willing to put into tracking a tire that already has a predetermined life?” Stuart asks.

Some fleets only track the first life of the tire, from new to the first reposition or recap. That will get you a vastly different number.

• Acquisition cost - $400

• Total miles to removal - 250,000

• Overall cost is dollars divided by miles - $0.002

Is the tire really nearly double the cost per mile? No, it’s just how you do the accounting.

At the other end of the spectrum we have Lloyd Hair, maintenance director at heavy-hauler Keen Transport. He can tell you to four decimal places what his tire costs are, and he has developed 120 codes to describe and account for why a tire might get pulled early from service.

Maybe key to the difference in Hair’s approach to tire management is the fact that Keen is a heavy-haul operation; the trucks can often run only during daylight hours, so stopping to fix a flat is out of the question. To Hair, tire maintenance is mission-critical. To that end, he tracks tires to within a 32nd of an inch of their lives.

“I want to identify where my problems are, what type of tire injuries I’m getting and where they occur, both the physical location as well as the spot on the tire,” says Hair. “Once you have identified the problems, you can start to manage them.”

Not many fleets can successfully manage tires at this level, so is it folly to even try?

Hair says the cost of his tires when you look at rubber only is about the same as everyone else’s, but the cost of his tire program is probably higher. He obviously sees value there, and on several fronts.

“I dig pretty deep to determine what the best tire is for my application,” he says. “And the extra effort also guides me in choosing the right tires.”

On the value of good tire maintenance, Hair and Stuart agree.

“You have to manage tires every day, every mile, every rotation,” says Stuart. “If you do everything right and you buy at the right price, you’re going to get the lowest possible tire cost.”