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September 29, 2008 1:55 AM, EDT

Experts Cite Driver Behavior as a Key Factor in Extending Service Life, Raising Efficiency

By Amy Zuckerman, Special to Transport Topics

This story appears in the Sept. 29 print edition of Transport Topics.

From maintaining optimum air pressure to avoiding jack-rabbit starts, a truck driver’s actions affect not only the life expectancy of tires but also a vehicle’s fuel efficiency.

“There’s a direct correlation between those driver behaviors that not only reduce tire life but then affect fuel economy. If a driver is driving efficiently, he will positively affect the life of his tires and improve fuel use,” said Pat Martindale, vice president of field maintenance for Penske Truck Leasing’s south-central region, Memphis, Tenn.

Not all tire wear and tear can be attributed to drivers’ maneuvers behind the wheel. Factors such as alignment and wheel balance also play key roles. But it’s easy for those who know what they’re looking for to correlate certain types of wear with driver behavior. And when tires wear badly, that can create drag, which affects fuel use.

Fuel economy experts report that driver behavior can affect fuel efficiency by as much as 25%, though savings of 5% to 15% may be more common, said managers at Isuzu’s “Fuel Economy Challenge” program, which teaches fleet executives how to modify driving behavior to create fuel savings. In addition, statistics from the National Academy of Sciences indicate that at least 2 billion gallons of fuel annually are wasted because of low tire pressure.

Tim Richards, project manager for linehaul commercial tires at the Goodyear Tire and Rubber Co., Akron, Ohio, said it can be “frustrating for operators and fleets who see one truck getting barely 100,000 miles before the steer tires have to be pulled, while another covering a similar route regularly runs more than 200,000.” He attributed the fact that some trucks achieve double the tread wear of others to the technology used in the manufacturing process, driving habits and maintenance practices.

Consider something as simple as tire inflation, which affects both tire wear and fuel use.

When tires are under-inflated, “the vehicle has to work harder to move forward, which creates drag and requires more fuel,” said Harvey Brodsky, managing director of the Tire Retread and Repair Information Bureau. Brodsky also said the tread on underinflated tires does not hit the highway properly, causing the tires to wear out prematurely or even break a sidewall.

“For every 10% low of pressure the tire runs, it prematurely wears 10% of its tread. Twenty-percent low wears out 20% faster,” said Phillip Zaroor, president of Advantage PressurePro, a supplier of tire-pressure monitoring equipment based in Harrison, Mo.

At fleets such as New Century Transportation Inc., Westhampton, N.J., tire costs run to $900,000 annually and are among the fleets’ top expenses, said John Liberkowski, the company’s vice president of purchasing. The company offers truckload and less-than-truckload services and maintains a fleet of about 1,000 trucks and trailers.

“We preach air pressure. We ask our drivers to keep a daily visual check on tires to see if they’re underinflated as part of a daily pre-trip inspection. They don’t expect they’ll carry a tire gauge, but they do need to knock the tires to make sure there’s a hard sound,” he said.

Brodsky agreed the driver is on the front lines of maintaining proper tire inflation, which has a direct effect on the tire’s life and whether it can be retreaded. He urges drivers to walk around their truck every day before setting off and to use the “dirty-hand test” at least once a week.

“Take your hand and rub around the portions of the tire you can reach — the sidewall and tread area,” Brodsky explained. “Your hand will detect an anomaly, stopping problems before they begin.” 

He also urges drivers to change tire gauges “about once a year, since most gauges will lose their accuracy after being banged around or dropped a few times. A small tire gauge will not cost much and is a good investment.”

Brodsky spoke favorably about automatic monitoring systems, which he said would prolong tire life, increase fuel mileage and decrease downtime.

One example is PressurePro’s system, which relies on a small sensor that screws into the tire’s valve stem. Zaroor said it reports tire pressure to an in-cab computer every five minutes. The driver can be alerted automatically when tire pressure changes by a certain amount, and the information also is relayed to an office management system.

Educating drivers about proper tire maintenance doesn’t stop with inflation. Liberkowski said something as simple as how a driver handles the steering wheel when backing up can make a difference on tire stress. New Century drivers are taught to “roll first and then crank the wheel,” he said.

“We ask them to pay attention to debris in the road and warn against bumping or hopping curbs when making turns. That’s like getting punched in the stomach. You may not feel it today,” Liberkowski said, “but it can bruise casings and break steel belts that will create problems later on.”

Similarly, Penske Truck Leasing holds informative customer-driver meetings that discuss tire management, Martindale said. The company also advises its customers on the status of their tires when vehicles are brought in for maintenance.

Martindale said a tire’s condition can tell a great deal about driver behavior. For example, hitting curbs can lead to tears along the sidewalls. Cuts in the treads can come from “running over debris rather than avoiding it. Hard braking is a contributor to accelerated tread wear,” he said, along with “hard stops.”

Goodyear currently is targeting driver behavior as part of a public education campaign that focuses on the role tires play in boosting fuel efficiency, said Tim Miller, the tire company’s marketing and communications manager for commercial tires.

“If you find that certain driver’s tires wear more quickly, that’s probably an indication that he is driving aggressively and burning more fuel, as well,” said Miller, based in Akron.

Conversely, Richards said an experienced driver can “achieve up to twice the removal mileage of a less experienced driver.” He said he knows of customers — mainly owner-operators who take “very good care of their equipment — that have run linehaul tires as much as 400,000 to 500,000 miles.”

Richards attributes poor driver behavior to “lack of awareness and training,” although both he and Miller are noticing far more driver monitoring taking place among fleet customers. Two behaviors they credit with having a major effect on tire tread and fuel use are:

Cornering, or making sharp turns, because it cuts a tire’s overall mileage and is a top contributor to worn tread, particularly at highway speeds. Even high wheel cuts in parking lots or highway off ramps accelerate tread wear, Richards and Miller said. They recommend that drivers plan ahead and know their routes to minimize sharp turns.

Scrubbing, or pushing the tire across the highway, because it will strip tread elements from a tire’s footprint. Heavy cornering at high speeds can cause scrubbing, as can fast acceleration, particularly when a tractor is carrying a heavy load. Tread can be stripped when pulling away from a loading ramp or with parking lot maneuvers.

“Any maneuver that contributes a lot of scrubbing of the rubber across the road is going to be a detriment to long mileage . . .  Experienced drivers make subtle lane changes and maneuvers that are gentler on the tire,” Richards explained.

“A driver sometimes doesn’t have much control over the load he’s pulling or the route he follows — but he has total control over how fast he takes those inclines,” Richards said. “Putting more torque on the tires and making them work harder reduces tire mileage” because speed increases scrubbing and wastes fuel.

Route selection also can play a major role in tire life and wasted fuel. For example, Richards said a driver whose routes cover mostly flat terrain will likely achieve better tread life than a driver running routes over hills. Miller knows of pickup-and-delivery operation managers encouraging more use of left turns and planning routes accordingly, “because right-hand turns are sharper,” with a deleterious effect on tire tread.