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Car and Driver Tests Ford Explorer in Blowout

30 October 2000

Car and Driver Tests Ford Explorer in Blowout; No Abnormal Problems at Low or High Speeds

    ANN ARBOR, Mich., Oct. 27 What happens when a left rear
tire on a 1994 Explorer blows on a paved straightaway at 70 mph?
"Surprisingly, not much," said Csaba Csere (pronounced Chubba Chedda),
editor-in-chief at Car and Driver magazine.
    "I'd trust my own mother driving in similar circumstances," said Csere
following a series of road tests that he and a team from Car and Driver
magazine conducted on Oct. 23 and 26.  Results of the tests, conducted at
Milan Dragway just south of Car and Driver's Ann Arbor headquarters, revealed
that, "during a tire failure, the Explorer, like other modern vehicles in our
experience, remains stable and easy to control," said Csere.
    "Nothing happened to explain why an Explorer, similarly equipped and under
the same conditions, might veer from the paved roadway.  And, unless the
vehicle leaves the pavement, a rollover is extremely unlikely."
    Csere speculated that some drivers panic or are startled by the sound of a
tire disintegrating or blowing out, then jerk the steering wheel or slam on
their brakes.  Even so, when Technical Editor Larry Webster, who drove the
test Explorer, fully applied the brakes during one blowout test at 70 mph, he
had no trouble controlling the vehicle.
    Car and Driver bought the used 1994 four-door, 4WD Explorer Oct. 20, at an
independent, used-car dealership in Redford Township, Mich., a suburb of
Detroit.  The vehicle was equipped with Goodyear Wrangler RT/S tires
(installed during the Firestone recall) and the odometer read 37,137 miles (a
figure Csere suspects is 100,000 miles too low).
    Car and Driver had a roll cage and competition seat belts installed to
protect the driver, but nothing else mechanically was done to prepare the
vehicle for the tests.  To record results, two video cameras were mounted: one
inside the vehicle, trained on the driver, and one outside the vehicle, aimed
at the left rear tire.
    The blowout was achieved by fitting a modified wheel with a special valve
that would deflate the tire in one-third of a second.  This device was
triggered remotely via hand-held transmitter.  The modified wheel was fitted
to the left rear tire of the Explorer because that position was the one most
commonly cited in the Firestone blowout complaints.
    With Webster at the wheel, Csere triggered the blowout once the vehicle
came up to speed.  "Since we were able to perform repeated blow outs, we began
our tests at 30 mph and worked out way up to 70 mph in 10-mph increments,"
explained Csere.  "Larry did not know exactly when the blow out would occur."
    In every case, even at 70 mph, the Explorer's performance was remarkably
undramatic.  When the blowout occurred, the left rear of the vehicle settled
down, but the Explorer continued straight ahead.  "I even kept my hands off
the steering wheel during one blowout at 70 mph, and the Explorer continued
straight.  Not until I applied the brakes, which pulled to the left, was I
forced to put a hand on the wheel and correct the Explorer's path," explained
Webster.
    Only after applying the brakes as hard as possible after a 70-mph blowout,
did the Explorer wiggle at all.  Even then it would have easily stayed within
the confines of a normal traffic lane, said Csere.
    Based on these results, Csere offers the following advice to drivers of
any vehicle, who suspect that they are experiencing a tire problem:

    -- Don't panic, modern vehicles tend to remain stable during tire
       failures.

    -- Keep the vehicle going straight and on the pavement. The chance of
       rolling over is minimal unless you leave the roadway.

    -- Unless there's an immediate obstruction in your path, don't be in a big
       hurry to stop.  The additional drag of the deflated tire will slow your
       vehicle down by itself pretty rapidly.  Ease your foot off the
       accelerator and apply the brakes gently to come to a full stop at the
       side of the road.

    "If you follow these guidelines, you have an excellent chance of making
sure that your tire failure remains an inconvenience rather than turning into
a tragedy," said Csere.
    Csere holds a degree in mechanical engineering from the Massachusetts
Institute of Technology.  He joined Car and Driver in 1980, has held positions
of technical editor and technical director, and has performed instrumented
tests on more than 800 cars.  Previously, he worked on fuel injection systems
at Ford's Advanced Engine engineering office.  Webster is a graduate of Lehigh
University where he majored in engineering, and he joined Car and Driver in
1994.  He is one of the magazine's main road test drivers.