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Goodyear Goes 'Flat Out' with New Technology

20 November 1997

Goodyear Goes 'Flat Out' with New Technology

    AKRON, Ohio, Nov. 20 -- Quick-fix flat-tire remedies on the
market today don't hold much air, according to engineers from America's
largest tire company.
    Despite widespread claims, tire inflators and sealant tires aren't
foolproof; and, while claiming to offer some security, they'll never eliminate
the spare tire completely, according to Bill Egan, chief engineer of advanced
original-equipment technology for The Goodyear Tire & Rubber Company.  Special
wheels and tire inserts also have their downfalls.
    "A spare tire is a better alternative to sealants and inflators," Egan
said.  "Although it's not always convenient to change a flat tire, until
recently a spare still out-performed every other option."
    Extended mobility technology (EMT), or run-flat tires, have changed all
that.  Thanks to an emerging Goodyear technology that eliminates the
inconvenience of disabling flats, spare tires are history for the 1998
Chevrolet Corvette and 1998 Plymouth Prowler, he added.
    The performance of the Corvette on Eagle F1 GS EMTs with zero inflation
pressure is so impressive, Egan said, that a low-pressure warning system is
required to alert the driver to any loss of pressure.
    Now the technology is coming to the family car.  In early 1998, the
company plans to extend the present EMT tire offering from the Corvette and
Prowler ultra-high-performance lines to standard high-performance tires.
    Several tire manufacturers and aftermarket companies are promoting
alternatives to extended mobility technology, Egan said, but each possess
pitfalls:

    * Sealants, first used in bicycle tires before the turn of the century,
      are only about 75 percent effective today at stopping leaks in auto
      tires, since the puncture must be in the tread area and not be larger
      than one-quarter-inch diameter, Egan said.

    However, when the sealant is effective, it masks impending tire failure
that could leave motorists stranded at a most inopportune time, he said.
    A sealant tire requires periodic inspection to make sure a nail or other
foreign object hasn't punctured the tread.  Without attention and repair, the
object eventually could loosen from the surrounding sealant and cause rapid
air loss.

    * Tire inflators, a stop-gap way to seal leaky tires, are even less
effective than sealant tires, he said.  Aerosol-type sealers and inflators,
some which use flammable propellant gases -- such as butane, propane or
isobutane -- make tire repair hazardous.
    The pressurized liquid must coat the entire inside of the tire, making the
repair doubly messy, Egan said.
    "Add the fact that nearly all liquid aftermarket sealants are water-based,
and you can see how moisture can enter all parts of the tire.  The only thing
you should put in your tire is dry air," he said.
    * Spare tires are the best alternative to extended mobility, despite the
inconvenience of a tire change.  The high-pressure convenience spare is
durable, with the predominant bias-ply tire capable of about 3,000 miles and
radials lasting about 5,000.  And handling is comparable to that of the
conventional tire, he said.
    Coincidentally, after sitting in a trunk for years, the 60-psi (pound per
square inch) convenience spare tire is prone to lose air.  Thus, most are run
under-inflated when they are needed, he said.

    * Special wheels and tire inserts usually are precluded from serious run-
flat consideration for cost reasons, Egan said.  Special wheels, which several
tire manufacturers used in the 1970s and '80s to keep the tire seated on the
rim during cornering, are relegated to limited applications due to expense.
Goodyear's EMT tires are effective on standard wheels, allowing motorists to
keep current and replacement costs affordable, Egan said.
    Goodyear also is a pioneer in tire inserts, most notably its tire-within-
a-tire Lifeguard safety spare developed in 1963.  An advanced Lifeguard system
still is used in NASCAR stock car race tires.  Other tire inserts, made of
metal or fiberglass composites, have been used in limited low-speed, heavy-
load applications, such as Goodyear's Wrangler tires fitted on presidential
limousines and on Hummer military vehicles.

SOURCE  Goodyear Tire & Rubber Company