By Richard Truett, Crain News Service©
DETROIT (July 10, 2001)—Ford Motor Co.’s team of about 100 engineers
plan to certify the safety and durability of tires supplied for its
vehicles by conducting a series of tests born out of its research into
Firestone tire failures.
The team will subject tires to various new tests, including:
c Measuring wedge thickness. The wedge is the rubber insert between
the steel belts that absorbs stress and heat created by the belts as the
tire turns. Wedges made too thin could cause trouble as the tire ages.
By tearing apart hundreds of tires, Ford has learned that heat will
cause a thin wedge to crack and the belts to separate from the tire
casing. Ford will look for consistency in the wedges on same-model tires
made in different plants.
c Monitoring tread temperature. High heat makes rubber age faster,
which leads to cracks and tread separation. Ford will use a non-invasive
method of measuring tread temperature to ensure that a tire won´t
overheat under load and with varying pressure. Ford engineers feel they
have advanced tire safety testing by measuring tire temperature while it
is in motion, rather than by stopping it and cutting into the tread to
measure heat buildup.
c Determining the amount of force it takes to pull the belts apart.
The greater a tire’s peel strength, the less chance of tread separation.
Other durability testing Ford will do in-house and with tire
companies includes measuring tire performance under extremely stressful
conditions, such as at high speed, high load and at high temperatures.
In testimony before Congress last month, Ford CEO Jacques Nasser said
the auto maker´s tire team has spent nearly 100,000 hours testing tires.
The cost: at least $25 million.
Ford spokesman Jon Harmon said that in addition to stricter in-house
tire testing at Ford´s Dearborn, Mich., headquarters, the auto maker
also is establishing an early warning system that links Ford to tire
suppliers’ warranty claims data. Ford’s toughened tire tests cover all
its vehicles, not just trucks.