Article

The Art and Science of Spec'ing Tires

Choosing the right tires involves analysis and research, trial and error, and a little guesswork.

July 2011, TruckingInfo.com - Feature

by Jim Park, Equipment Editor, Equipment Editor - Also by this author

SHARING TOOLS        | Print Subscribe

Tires are a big part of the fleet maintenance and operations puzzle. They serve an obvious purpose, but how well they perform in the operational theater is key to a successful tire program. What's important in a tire to one fleet may not matter at all to another.

Is it longevity and resistance to irregular wear? Brand loyalty and a good relationship with a service provider? Retreadability? Or good old-fashioned price?

Tires are like thoroughbred horses these days: designed for a purpose. According to fleet supervisors we talked to, what seems to set one tire apart from another is how well they handle curve balls - the unintended consequences of operating outside their intended application.

Colonial Cartage of Kennesaw, Ga., is a regional refrigerated LTL with 60 power units, 140 trailers and two straight trucks. Fleet manager Joe Ruzicka says his tires do double duty as highway tires and urban tires.

"We want the performance, efficiency and tread life we get from an on-highway tire for the time the trucks are in transit, and when they arrive at destination, we want a tire that offers scrub protection and resistance to scuffing from the multi-drop work," he says. "They'll spend the day alley docking, backing over curbs, and negotiating tight turns. That's murder on steer tires and trailer tires."

Like Ruzicka, Rick Stenli, fleet maintenance supervisor, Air Liquide America Corp., needs tires to perform equally well in several arenas: on-highway, urban multi-drop, and while parked for weeks at a time at a customer facility.

Air Liquide is a bulk tanker fleet where payload is king. Based in Madison, Wis., it runs 450 tractors and 750 tank/tube trailers in the U.S. The company is transitioning to wide-base single tires for the weight savings, but is finding that some single tires don't respond well to sidewall damage.

"That's our biggest challenge with the wide-single," Stenli says. "We're in a high-scuff environment. Access to some of our customer storage tanks is a real challenge, and it just tears up tires. We're not yet seeing the same scuff and curb resistance on the wide-singles that some regional-specific duals have."

Stenli has been experimenting between regional and longhaul steer tires. He is now seeing 140,000 miles from the longhaul tires in regional applications, which he considers very good. His regional tires, on the other hand, are averaging 80,000 to 120,000 miles in the combined longhaul and urban environments.

"The regional tires respond better to scuffing, but overall aren't delivering the same mileage the on-highway tires do," Stenli says. "Because our routes vary so much - one truck could do 50 miles one day and 500 miles the next - we can't really divide the fleet into groups of regional or longhaul. They have to take what ever we throw at them. And then we hope to get three recaps out of a casing. It's a pretty tall order."

Retreads and shallow treads

Deeper treads traditionally have done a better job in high-scrub environments, but they aren't conducive to good fuel economy at highway speeds. Ruzicka has found, to his surprise, that a shallower, fuel-efficient tread is doing very well in the regional environment. He runs some low-rolling-resistance retreads on his drives and trailers and says they are working quite well.

"I was reluctant to go to a shallower 11/32 tread given our urban exposure, but it has worked out better than I expected," he says. "I was concerned about rapid tread wear, but they are holding up and actually running cooler than the deeper, 18/32 tread on the regional tires. I think that's going to improve retreadability, too."

Colonial typically gets one cap per casing, but the tires are usually about five years old by the time cap is worn out. The trucks run about 60,000 miles annually.

Stenli, too, will take a casing out of service at five years, but his may have been recapped up to three times.

Both fleets say tire inflation is one of their biggest challenges. Consis­tent inflation and long tire life go hand in hand, and it becomes even more critical with retreads. Casing life depends proper inflation.

Stenli is currently evaluating an automatic tire inflation system, along with a tire pressure monitoring system. He currently uses wheel-end-mounted tire pressure indicators, which he says aren't perfect, but better than guessing.

Ruzicka say his tire service provider looks after inflation during yard checks of whichever trailers happen to be in the yard when the service truck comes around. He says about half the fleet gets checked by the tire company at least once a month. He too says an automatic tire inflation system will be included with the next bunch of trailers he buys.

"Retreads, hot weather, hot roads; a bad combination," he notes. "We buy a lot of tires."

The customer is king

In Church Hill, Tenn., Dan Roe looks after a fleet of glass haulers at Flanary and Sons Trucking (FAST). They run 118 flatdeck, single- and double-drop trailers and 80 power units.

"Our biggest concerns are payload and on-time delivery," he says. "We used to run duals all around, but we've had to switch to wide-singles to get the weight down."

He says they were worried about excessive and irregular wear, and driver perception of the tires. He was also concerned, at one time, about availability of replacements.

"We started out on 455/55R22.5, but we're now on the 445/50R22.5," he says. "The 55s are a little harder to find out there, but everybody has the 445/50s. We can't afford to be down, so we had to ensure we could get replacements when we needed them."

Roe runs an automatic tire inflation system on some of the trailers, and he uses nitrogen in his drive tires to maintain inflation.

He says the wide-base single tires on the trailers are wearing better than he expected, and he hasn't had a single tire-related delay since he installed them. As for the nitrogen inflation, he has evidence that tires are running cooler and maintaining inflation pressure better between pressure checks.

Even the drivers have embraced the wide-base single tires, despite early reservations about possible downtime and wet and winter traction.

"We switched over to wide-singles from duals because we had to," Roe admits. "We went for the weight savings, got fuel savings too, and now everyone is pretty happy with the switch."

Owner-operators

If there's a group at some disadvantage when it comes to tire spec'ing, it's the owner-operator and really small fleet. Even if they were in a position to run extensive evaluations on tires and various add-ons, the test samples would be too small to be meaningful, and if the product is in testing long enough, chances are some better product will have come along in the interim.

Henry Albert does his tire research in truckstop parking lots. He's a single-truck operator currently part of Freightliner's Slice of Trucker Life truck evaluation and blogging program.

"I always park in the back row and like to wander through the lot looking at tires on other trucks, big fleet trucks usually, to see what they are running. I figure they've done the research I can't do," he says. "I'll watch specific tires and note their condition on various trucks to see how they are holding up. Sometimes I'll ask the driver about the tires to check mileage, age, etc. to see how the tire is performing."

He watches trade magazines and truck trade show displays to learn what's new in the market, and he asks a lot of questions.

"I have a good idea what's out there, but I have to validate what I hear from the tire people with some real world experience," he says.

Albert also runs an inflation system on his trailer, and uses a combination balancing/sealing compound in all his tires as a hedge against wear and punctures.
There's always something new coming down the pike, so it pays to keep an open mind when it comes to tire spec'ing. As Roe discovered, switching tire types proved the right move even though it wasn't something they had planned to do. And in Ruzicka's case, going with a shallower tread has proven beneficial, even though the move was counterintuitive at first.

Spec'ing for the real world means getting out into the real world, and really getting to know your operat ing environment, and sometimes bending the rules a little bit. And like Albert, watching what the other guys are doing.

ADVERTISEMENT

Comment On This Story

Name:  
Email:  
Comment: (Maximum 2000 characters)  
Leave this field empty:
* Please note that every comment is moderated.

Newsletter

We offer e-newsletters that deliver targeted news and information for the entire fleet industry.



GotQuestions?

LUBRICANTS

The expert, Mark Betner from Citgo will answer your questions
Ask a question

Sponsored by


WHEEL ENDS SOLUTIONS

Wheel end expert Jeff Geist from STEMCO will answer your questions
Ask a question

Sponsored by

Magazine