Your Daily Tread
High fuel prices not only are taking their toll at the pump, they are affecting tire prices as well. Oil is a major ingredient in the manufacturing of all tires. As such, you need your tires to take you as far as possible. And there are several things you can do to extend their life. One simple and immediate way for you to make the most of your fuel and tire money is to pay greater attention to proper tire maintenance. This is critical for both new and re-treaded tires. What follows are some tips to enhance performance and ensure that you are maximizing the wear you are getting from your tires.
Air pressure is at the heart of proper tire maintenance. By maintaining the correct inflation pressure for a given size of tire and load, tires will provide the best fuel mileage and safety, while minimizing wear and maximizing retreadability. Tire manufacturers have tables and charts (available free for the asking) that specify air pressure adjustments for tire size, load and speed. These charts are also available from the Tire Retread Information Bureau (TRIB). (See “Tire treatment,” page C15.)
It is important to realize that it is the air inside the tire that carries the weight of a vehicle, not the tire. The air supports the weight, absorbs shock and keeps the tire in its proper shape, allowing it to perform as designed. The tire serves as the container for the air.
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 (the portion that contacts the road surface). Because the tire doesn't roll as smoothly or as easily as it was designed to, fuel efficiency declines, as the engine has to work harder to keep the vehicle moving.
Tires are made of layers of fabric and steel cords encased in rubber. Tires flex when they roll, which bends these components. Underinflation is a major contributor to premature tire problems because underinflated tires cause excessive flexing, which generates heat, and heat is a tire's worst enemy. There is a direct correlation between how much a tire is underinflated and how much faster it wears.
Underinflated tires tend to run hotter, diminishing retreadability. This is significant because retreading makes it possible to re-use worn tires, allowing the best possible return on tire investments, and that helps improve your bottom line.
Retreading is a process where worn tires receive a thorough visual inspection, followed by the use non-destructive inspection equipment to uncover damage invisible to the naked eye. This equipment ensures that the casing is a prime candidate for a full and useful additional life.
Tires that pass the rigorous initial inspections then have their worn tread precisely buffed away, preparing the casing surface to receive a new tread. Next, any injuries to the tire are repaired and the new tread is then securely bonded to the tire in a method similar to the manufacture of a new tire.
Retreaded tires provide the same performance and safety record as new tires but at a lower cost — as much as 50 percent less. The more expensive the original new tire, the greater the retread savings.
Every major quality commercial and industrial tire manufacturer designs and engineers its tires with robust casings for several retreading lives. So to discard a worn tire without retreading is to lose much of the tire's value.
You should pay particular attention to 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. The result: rapid and irregular wear, especially on the smaller tire.
Always check tire pressure when a tire is cold. That is, before you have driven the vehicle or have driven it less than one mile. Once a vehicle has been driven, even a short distance, tires warm up and experience an increase in air pressure and that causes an inaccurate reading.
Check tire pressure 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. 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 the hood.
While gauging inflation, perform the “dirty hand test”: Rub your hands over the tires to feel for any abnormalities like flat spots, bulges, cuts, damage and missing chucks of tread. Such problems not only can result in tire failure, they can also lead to accidents.
It is a good idea to install value caps on all valve stems and keep to them tight. This provides seal against valve leaks and keeps out dirt and water. Metal value caps are best as they contain a rubber gasket to provide an airtight seal. Most plastic caps do not.
Even well-maintained tires lose air pressure: on average, about one or two pounds per month. This is a natural occurrence as air permeates through rubber.
You can do several things to help maintain proper tire inflation. One is to fill tires with nitrogen instead of compressed air. Nitrogen allows a tire to retain more of its original properties so that there is less inflation pressure loss for a more stable and consistent tire pressure, longer tread life and less oxidation of tire components. This assists in increasing tire life, improving fuel economy and reducing tire aging for a more durable casing for more retreadability.
Another option is the use of various tire-pressure monitoring and control systems. Some warn of low pressure. Others equalize air pressure for slow leaks. Still others help maintain air in a tire that is damaged, enabling the driver to get to a repair facility.
A sound tire-management program involves purchasing application-specific quality new tires, good air pressure maintenance, proper tire repairing and quality retreading. In addition, you should track tire performance and analyze scrap tires.
Finally, do not overlook the driver of your vehicles. They are yet one more key factor impacting fuel efficiency, tire life and retreadability. All tires will wear faster when subjected to hard cornering, rapid starts, sudden stops and curbing.
Harvey Brodsky is managing director of the Tire Retread Information Bureau (TRIB), a non-profit, member-supported industry association dedicated to the recycling of tires through retreading and repairing, and to promoting proper tire maintenance for all tires. To learn more, contact TRIB at (888) 473-8732 or at email@example.com. TRIB's Web site is www.retread.org.
For charts that specify air pressure adjustments for tire size, load and speed, you can contact the Tire Retread Information Bureau (TRIB) at (888) 473-8732 or at firstname.lastname@example.org.