Firestone and Ford Make Progress on Tire Inquiries
December 15, 2000
By KEITH BRADSHER

DETROIT, Dec. 14 — Firestone and Ford Motor have made considerable progress
in their investigations into the tire-related crashes that have killed
more than 100 Americans, mostly in Ford Explorers, but they remained
divided on some basic issues as they presented their results to regulators
this week, people close to the inquiries said.
Ford's newest finding is that a Firestone factory in Decatur, Ill.,
followed procedures different from those at other factories in handling
rubber and other incoming materials, and these procedures may have allowed
the quality of the materials to degrade, a person involved in the inquiry
said. The steel-belted radial tires made in Decatur have had a much higher
failure rate than tires of the same brands made elsewhere, according to
Firestone and Ford.
Sanjay Govindjee, an engineering professor and tire expert at the
University of California at Berkeley retained by Firestone to conduct a
separate review, said that preliminary results from tests conducted for
him by Firestone provided little evidence for a possible problem cited in
a Firestone preliminary report five weeks ago. During normal driving, the
motion of the Explorer does not appear to put unusual stress on its tires
that would cause them to fall apart faster than usual, he said in a
telephone interview.
The Explorer does have an uneven weight distribution that puts an extra
load on the left rear tire, Mr. Govindjee said. A disproportionately large
share of the fatal crashes have involved failures of the left rear tire.
But the extent of the extra load appears to vary considerably with the
location of the people and luggage in the vehicle, Mr. Govindjee said,
adding that he had not determined whether the extra load was a factor in
the tire failures. The current Explorer has the gas tank and the
four-wheel-drive system on the left side of the vehicle; Ford has moved
the gas tank to the right side for next year's model, improving the
vehicle's balance.
The two companies have made further progress in isolating two other
problems identified in Firestone's preliminary report, people close to the
companies' investigations said. These problems are a tendency for cracks
to develop in the rubber between the layers of the tread and problems in
the design of the rubber wedges that fill the space between the edges of
the steel belts.
But Firestone and Ford are still at odds over the appropriate scope of the
investigation, people close to both companies' reviews said. Partly as a
result, the companies have presented their findings separately to
regulators this week. Officials from the National Highway Traffic Safety
Administration spent Monday and Tuesday at Ford's headquarters in
Dearborn, Mich., and are in meetings today and Friday at the headquarters
of Bridgestone/Firestone Inc. in Nashville, people close to the companies'
investigations said.
Eager to exonerate the Explorer, the nation's best-selling sport utility
vehicle for the last 10 years, Ford is contending that the inquiry should
be limited to why the tires failed in the first place, usually when the
treads peeled off during highway driving. But people close to Firestone,
which is a unit of the Bridgestone Corporation of Japan, say that an
assessment of what went wrong should go beyond the tires, to the question
of why the tire failures caused so many deaths. Tread separations are the
most common form of tire failure, yet the separations have proved to be
unusually deadly on Explorers.
Firestone officials have emphasized that almost all of the tire-related
deaths occurred in Explorer sport utility vehicles that rolled over. Ford
officials respond that all sport utility vehicles roll over more readily
than cars and that all sport utility vehicles are thus more vulnerable to
tire failures than cars.
John Lampe, Firestone's chief executive, criticized the stability of sport
utility vehicles during Congressional testimony in September but did not
say that the Explorer was more likely to roll over than other sport
utilities. In an interview in October, Mr. Lampe said that Firestone did
not have any evidence that the Explorer was worse than other sport
utilities in terms of stability but contended that all sport utilities
posed a problem because their instability made them hard to control in the
event of tire problems.
A computer analysis by The New York Times of a federal database of all
fatal crashes nationwide over the last nine years found that rollovers
were a factor in four-fifths of all tire- related deaths in sport
utilities other than the Explorer — less than the Explorer's rate but far
higher than the two-fifths of the tire-related deaths in cars. The annual
death rate in tire-related crashes per million vehicles has consistently
been 50 percent to 60 percent higher for sport utilities, even excluding
the Explorer, than it has been for cars, the analysis found.
Mr. Govindjee, an expert on the chemical properties of tires, said that he
was not looking at the rollover issue in his analysis because it was
outside his area of expertise. He added that he was also not looking at
the 16-inch or 14-inch tires that have not been recalled because he did
not have time to do so before the end of this year, his deadline for a
report to Firestone.
Firestone is also trying to determine what if any effect there may have
been from two batches of defective parts on Explorers that Ford recalled
this month. Ford has recalled 800,000 Explorers to replace a front
suspension component that limits the vehicle's tendency to lean and
110,000 Explorers to replace a defective computer chip in the engine that
fails to limit the vehicle's top speed to 106 miles an hour.
The vehicle's tires are certified only to last 10 minutes at 106 miles an
hour, prompting questions from Congressional investigators about why there
was no safety margin at top speeds even when the chips worked properly.
G.M. says that it sets the computer chips in its sport utilities for a top
speed that is 14 miles an hour lower than the top speed of the tires.
Ford, which said in September that the Explorers' chips set a top speed of
only 99 miles an hour, says that the front suspension problem and the
computer chip have not contributed to the tire-related crashes.
Ford and Firestone remain opposed to broadening the tire recall beyond
those already recalled, people close to both companies said. The tires
recalled so far are 15-inch ATX tires produced at various factories from
1990 to 1996, and 15-inch Wilderness AT tires made since 1996 in Decatur.
Personal injury lawyers want the recall expanded to cover 15- inch
Wilderness AT tires made at other Firestone factories and to include
14-inch and 16-inch Wilderness tires as well. This would more than triple
the number of recalled tires.
"We intend to continue pressing them" to widen the recall, said Ralph
Hoar, the founder of SafetyForum.com, a research firm that works for

personal injury lawyers who sue makers of cars and tires.