Extending Tire Life

Using technology to help maintain proper air pressure provides numerous benefits

A simple and immediate way to make the most of the money spent on fuel and tire purchases is to pay greater attention to proper tire maintenance, the heart of which is air pressure. By maintaining the proper inflation pressure for a given size of tire and load, tires will provide the best fuel efficiency and safety, while minimizing wear for longer tread life and maximum retreadability.

The challenge has always been how to maintain the proper inflation pressure. The task can be made more manageable through the use of such technology as nitrogen inflation and tire pressure monitoring system.

It is the air inside the tire that carries the weight of a vehicle, not the tire, explain tire professionals. The air supports the weight, absorbs shock and keeps the tire in its proper shape so it may perform as designed. Tires, which serve as the container for the air, are designed to be run at a specific pressure based on how the tire is constructed and the amount of weight that it is carrying.

In addition to affecting rolling resistance, and thus fuel economy, inflation pressure also influences handling, traction, braking and load-carrying capability.

Improperly inflated tires have an uneven, irregular and inconsistent tire footprint (that portion that contacts the road surface), tire professionals point out. Because the tire doesn't roll as smoothly or as easily as it was intended to, fuel efficiency declines, as the engine has to work harder to keep the truck moving.

Tires are made of layers of fabric and steel cords encased in rubber. Tires flex when they roll, which bends these components.

Tire manufacturers agree that underinflation - when a tire has lower than specified air pressure - is a major contributor to premature tire failure and poor tread life problems. The reason being: underinflated tires generate a surplus of heat through friction and additional flexing of the steel belts which generates heat, and heat is a tire's worst enemy.

Excessive heat build-up in the tire creates dangerous driving conditions, they note, and also shortens tire life by rapidly increasing tread wear. There is a direct correlation between how much a tire is underinflated and how much faster it wears.

Underinflated tires also cause more frequent blowouts and punctures, requiring costly road service.

Because underinflated tires tend to run hotter, retreadability is diminished.

Truck and bus tire manufacturers design their tires to be retreaded, so it's important to protect the casing for reuse through retreading.

Another cause for concern is tire pressure in mated dual tire and wheel assemblies. Inflation mismatches on these tires can cause tire diameters to differ enough that the larger tire will drag the smaller tire. This results in rapid and irregular wear, especially on the smaller tire.


Tire pressure should always be checked when a tire is "cold," which tire professionals say, is before a vehicle has been driven or driven less than one mile. Once a vehicle has been driven, tires warm up and experience an increase in air pressure and that causes an inaccurate reading.

They also recommend that tire pressure be checked regularly, at least once a week, and always with a properly calibrated tire gauge. Inflation pressure cannot be accurately estimated by kicking or thumping the tire. As one tire professional put it: "Trying to determine if tires need air by thumping them is as effective as trying to determine if the vehicle's engine needs oil by thumping on the hood."

In spite of the fact that regularly checking tire pressure is one of the most important maintenance procedures, it is one of the most difficult to enforce. And even with the best preventive maintenance programs, maintenance personnel too often overlook checking some tires or even entire vehicles. Moreover, even the best of maintenance programs can't prevent tire damage resulting from a loss of air pressure while on the road.


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