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Goodyear: Tire Inner Liners Add to Tire Durability

18 October 2000

Goodyear: Tire Inner Liners Add to Tire Durability

    AKRON, Ohio, Oct. 17 Paying more for some of the "brand"
tires at the local tire store is more than just hot air, according to
engineers for America's leading tire company.
    In fact, the more costly tires usually retain air better than their less
expensive cousins, they say, in addition to lasting longer, riding quieter,
delivering improved traction and handling better.
    For example, only a few tiremakers build specially formulated inner liners
into all of their tires to help hold air.  Tires properly inflated with air
deliver improved fuel economy and longer tire life -- two factors that can
impact motorists' pocketbooks, according to Bill Egan, chief engineer of
product design for The Goodyear Tire & Rubber Company.
    The Society of Automotive Engineers reports that 87 percent of all flat
tires have a history of underinflation.  Since Goodyear added special liners
-- which contain a substance called halogenated butyl rubber -- to its tire
lines in 1984, its warranty claims have dropped dramatically, Egan said.
    Tires without these liners can lose twice as much inflation pressure -- up
to 15 pounds per square inch in a year -- than tires with inner liners, Egan
said.
    Running a tire 20 percent underinflated -- which is only 4 to 5 pounds per
square inch -- reduces tire life by as much as 15 percent and increases fuel
consumption by as much as 10 percent, he added.
    The inner liners in tubeless tires function the same as butyl inner tubes
did in old tube-type tires in stemming the natural escape of air through a
tire's layers of rubber.  But even with these liners, Goodyear recommends that
motorists check tire inflation pressure monthly or before a long trip.
    "These liners remain the least costly way for motorists to save on their
fuel and tire costs, and yet only a few tiremakers build them into all of
their products," Egan said.  "Selecting tires with inner liners and
maintaining inflation pressure over the tire's life is more cost-effective
than buying tires that have expensive fuel-efficient designs and materials."