DETROIT -- Ford Motor Co. will now recommend that Ford Explorer
owners inflate their tires to 30 pounds a square inch after
Bridgestone/Firestone Inc. criticized the auto maker in Congressional
testimony for setting the pressure too low.
The auto maker released a letter Friday saying it
was making the move because the company's
testimony "has caused confusion among our
"In these trying times surrounding the Firestone tire recall, it is
important to eliminate this confusion for our customers," Carlos
Mazzorin, Ford's group vice president for global purchasing and South
America, said in the letter.
Mr. Mazzorin also noted that Bridgestone/Firestone had agreed with
Ford's recommended pressure of 26 psi for 10 years on the Explorer's
Among tires that are not subject to the recall, Firestone and Goodyear
tires on Explorers inflated at that level "have shown excellent
performance for our customers," he said.
The letter says the pressure recommendation applies to Explorer
owners with Firestone P235/75R15 tires. It does not say whether it
applies to other tires installed on the Explorer.
A Ford spokesman said no one was available to comment on the letter.
The move comes after a Bridgestone/Firestone executive told Congress
on Thursday that the 26 psi level Ford recommends for Explorers is
lower than what Bridgestone/Firestone suggests and makes the popular
sport utility vehicle less safe.
"We now know that at 26 psi there is a low safety margin for the
Explorer as compared to some other SUVs," Bridgestone/Firestone
executive vice president John Lampe said. "Running an Explorer on low
tire pressures, overloaded, in hot climates appears to be a part of the
problem that we're now facing."
Bridgestone/Firestone, a unit of Japan's Bridgestone Corp., last month
recalled 6.5 million ATX, ATX II and Wilderness AT tires, most of which
were original equipment on Explorers. Federal investigators are
investigating the possible role of the tires in more than 100 deaths and
A lower air pressure gives tires more grip and a softer ride, but causes
them to wear faster and creates more internal heat because of greater
friction with the road. Ford has said it set the recommended pressure
for Explorer tires at 26 psi in 1989 to improve stability and ride, and
that Bridgestone/Firestone had agreed with the recommendation at the
But experts for trial attorneys suing the two companies have speculated
that heat from the lower pressure weakened the bond between the tires
and their treads. Thousands of people, most of them Explorer owners
in warm-weather states, have reported tread separations, blowouts and
other problems with the tires.
Ford has consistently blamed the problems on Firestone, and said the
design of the Explorer was not at fault.
When the recall was announced in early August, Bridgestone/Firestone
recommended that its tires on the Explorer be inflated to between 26
and 30 psi, but has been emphasizing that 30 psi was a safer level.
Ford had continued to recommend 26 psi, though it has acknowledged
that a range of a range of 26 to 30 psi was acceptable.
Mr. Mazzorin's letter says that as recently as Aug. 18,
Bridgestone/Firestone said the 26 psi recommendation was not a
mistake. After the hearing Thursday, a Bridgestone/Firestone
spokeswoman could not cite any testing the company had done recently
to decide that 26 psi was unsafe, but said the tire industry accepts 30
psi as the best level.
The National Highway Traffic Safety Administration began investigating
the Firestone tires in May. NHTSA Administrator Sue Bailey said the
agency now is examining how speed, temperature, load and tire
pressure affect safety on SUVs.
Mr. Lampe said Firestone still has not determined what caused some of
its tires to fail, but has focused on possible manufacturing problems at
its plant in Decatur, Ill.
Mr. Mazzorin said the tire pressure change "does not address the root
cause of the Firestone tread separations" and said the companies
needed to find the causes of "the tire manufacturing and/or design