Firestone told NHTSA that tests by an expert at Ohio State University shows certain Explorer models "oversteer" following a tread separation on a left rear tire and are "not safe at highway speeds in the hands of an average driver. This must be regarded as a highway safety defect within the meaning of NHTSA's charter."
"When a driver of a vehicle has something happen such as a tread separation, they should be able to pull over not rollover," said Firestone CEO Jim Lampe.
The driver, wearing special safety gear, walked away and challenged Ford's longtime claim that the people should simply be able to control Explorers if the tread separates. But Thursday, he told CBS News many SUVs oversteer when a tire treaseparates, not just the Ford Explorer.
Ford said when there's a tread separation, "the Explorer performs the same as competitive SUVs" and "the problem does not exist with Goodyear tires." Firestone request to investigate Explorers stopped short of a formal petition, which would have forced NHTSA to determine if the Explorer has a problem. NHTSA will only say it will look at Firestone's data.
Earlier this week, Venezuela's consumer protection agency asked the attorney general to seek a nationwide ban on Ford Explorer sales, saying design flaws may have caused 50 road accidents since August.
But it was unclear whether a ban would actually be ordered.
Agency president Samuel Ruh met Tuesday with prosecutors to offer what he says is evidence that failing parts in Explorers contributed to 50 rollover crashes that killed 37 people since August.
Ruh declined to comment after the meeting, saying he was legally prohibited from speaking about the case. A source at the attorney general's office, speaking on condition of anonymity, said an initial study indicates that prosecutors have no legal authority to act on Ruh's request.
Venezuelan Ombudsman Germain Mundarain publicly criticized Ruh's action, saying that "protecting consumers' rights does not have to involve prohibiting the sale of the vehicles."
Bridgestone-Firestone and Ford's Venezuelan units staged a bitter public feud last year over whether faulty Explorer design or Firestone tire failures or both were responsible for rollovers.
Last year, Firestone began quietly documenting Explorer accidents in Venezuela involving other tires.
U.S. federal safety investigators last week contacted Venezuelan authorities to look at their new data.
Firestone and Ford have never agreed on what caused the string of recent accidents the U.S. government is investigating, totaling 6,000 complaints citing tire problems like blowouts or tread separations, resulting in 174 fatalities and more than 700 injuries.
The accidents led last August to Firestone's recall of 6.5 million ATX, ATX II and 15-inch Wilderness tires made in Decatur, Ill.
Last week, Ford called for replacement of all Wilderness AT tires 15-inch, 16-inch and 17-inch, original and replacement tires. Eighty percent of the tires involved are on Ford Explorers, but they are also on some Expeditions, Rangers, F-150s, Broncos and Mercury Mountaineers.
Federal investigators were looking into a total of 55 million Firestone tires. The Firestone and Ford recalls now account for about half of those.
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