Firestone Asks Federal Agency to Test Safety of Certain Ford Explorer Models
By CLARE ANSBERRY
, STEPHEN POWER and J
OSEPH B. WHITE
Bridgestone/Firestone Inc., in a bid to get federal safety regulators to shift their focus away from its tires and toward Ford Motor Co.'s Explorer SUV, has asked government officials to investigate certain models of the popular sport-utility vehicle.
Firestone's request for an investigation of the Explorer is a highly unusual and potentially risky step for the tire maker in its deepening feud with Ford. The National Highway Traffic Safety Administration previously has looked into the stability of other SUVs but never found them to have inherent design flaws that would cause them to tip over. But Firestone wanted to present NHTSA investigators and Congress with as much ammunition as it could in advance of hearings on Capitol Hill into the safety of both companies' products, expected to begin later this month.
In lobbying for an investigation, Firestone said a new analysis showed certain models of Explorers will experience an "oversteer" condition in most circumstances following a tread separation on a left rear tire. The rear tire is significant because a large percentage of tires that have failed on Explorers, resulting in deadly rollovers, were rear ones.
In a letter to L. Robert Shelton, the NHTSA's acting administrator, Firestone Chief Executive John Lampe said the vehicle and tire are an "integrated system" and must be looked at together. "What affects one, affects the other. We ask NHTSA to investigate to determine the cause of the serious safety issue with a substantial segment of Ford Explorers and to take the necessary steps to remedy the potential defect so as to protect motor vehicle safety," he wrote.
"Oversteer" is a cornering condition in which the front of a vehicle turns more sharply than the driver intends during a turn, while the vehicle's rear skids around. A vehicle that oversteers is increasingly difficult to control as speed increases, according to the Firestone study.
Firestone, a unit of Japan's Bridgestone Corp., provided the NHTSA with the analysis, conducted by Dennis A. Guenther, professor of mechanical engineering at Ohio State University.
Based on his initial findings, Mr. Guenther said he believes the Explorers as tested are "defectively designed" because they don't provide an adequate margin of safety to permit control by average drivers. "An oversteer vehicle is not safe at highway speeds in the hands of an average driver," he reported.
Longtime observers of the NHTSA said they couldn't recall the last time an auto-related company had asked regulators to investigate a fellow company.
The latest move continues the escalating battle between Firestone and Ford over blame and responsibility for tires failing on Explorers. In August, Firestone recalled 6.5 million tires, mounted mainly as original equipment on Explorers. Federal safety regulators have linked those tires to 174 traffic deaths and more than 700 injuries in the U.S. alone, mostly involving rollovers of the Explorer that occurred after the tires suddenly lost their treads.
Last month, Ford said it would replace at its own cost as many as 13 million Firestone tires that weren't subject to the recall, because the auto maker lacked confidence in the tires. Firestone said it would cease doing business with Ford in North America, South America and Latin America, saying it no longer trusted the Dearborn, Mich., car maker and that Ford refused to address serious safety concerns with the Explorer.
In considering Firestone's petition, the NHTSA is likely to consider how the Explorer performs with non-Firestone tires. The agency also would look at accident data involving SUVs with roughly identical weight and size characteristics as the Explorer. So far, the agency has said it views its investigation of the Firestone recall as a "tire investigation."
The issue of oversteering isn't new to either Ford or the NHTSA. In a lengthy presentation to the agency's officials in March, Ford presented its own test data that showed Explorers could tend to oversteer during a rear-tire separation, and potentially spin out of control as the rear end slides.
Ford's safety experts argued that "the controllability of Ford Explorers is typical of other vehicles in the compact SUV segment during and after a tread separation event," according to Ford's report to the agency.
"All of these vehicles with a tread separation on an outside rear tire ... go to oversteer," Ford spokesman Ken Zino said last week, commenting on the technical data and charts in Ford's March report. "There's nothing unusual about the Explorer."
But Ford's report also contains evidence that passenger cars, which have lower centers of gravity than SUVs, tend not to lose control as easily during a tread separation. Ford's report cites a 1999 study by engineering consultants Richard J. Fay and Ric D. Robinette, which found that when a Ford Taurus suffered an artificially induced tread separation on a test track "little or no corrective steering action was needed to maintain control of the vehicle." Mr. Fay's full report concludes the Taurus "did not exhibit any appreciable change in handling or controllability during and after the tread separation.
Mr. Fay, head of Fay Engineering Corp., confirmed those results in an interview.
What makes Firestone's move risky is that the agency has never found inherent design defects in other SUVs that would make them prone to roll over. In 1990, the agency closed an investigation of the Ford Bronco II without finding a defect and rejected a petition for an investigation of the Chrysler Jeep CJ around the same time. Similarly, in the late 1990s, the agency rejected a petition for an investigation of the Isuzu Trooper.
If the NHTSA doesn't find any defect with the Explorer, Ford will be able to use the results of the investigation in court to exonerate itself. Hundreds of individual lawsuits have been filed against both Ford and Firestone.
"Tread separations remain a rare event, and fewer than 7% of tread separations on Explorers result in a rollover," said Mr. Zino, the Ford spokesman.
Ford continued to press its attack on Firestone by citing its experience with Goodyear tires used on 500,000 Explorers. Ford says it knows of no Explorer rollovers related to Goodyear tires following a tread separation, and the auto maker has no reports of serious accidents or injuries linked to Goodyear tires, Mr. Zino said. Ford said it has received just two complaints related to Goodyear tire-tread separations.
Mr. Lampe, Firestone's CEO, said tread separations happen on all brands of tires. "There are numerous incidents of Explorers rolling on competitors' tires. When this happens a person should be able to pull over and shouldn't roll over," he said.