Ford Explorer has a higher accident & rollover rate than comparable SUVs. Tire failures and tire defects are not the sole cause of these rollovers and deaths. The stability / design of the Explorer is under investigation by NHTSA

WASHINGTON -- >From the beginning of the Firestone tire recall, Ford Motor Co. officials have insisted that the accidents that killed 101 Americans, most of them in Ford Explorers, are a Firestone tire problem.
"There are more than 3 million Goodyear tires on Ford Explorers that have not had, as far as we know, one tread separation problem," Ford President Jacques Nasser told Congress. "So we know that this is a Firestone tire issue, not a vehicle issue."

A Washington Post analysis of national and Florida crash statistics shows, however, that the Ford Explorer has a higher rate of tire-related accidents than other sport-utility vehicles -- even when the popular SUV is equipped with Goodyear tires. The finding suggests that something about the Explorer may be contributing to these accidents, auto analysts said.

James Fell, who retired last year as chief of research at the National Highway Traffic Safety Administration, said the findings give "an indication that there may be a factor with the Ford Explorer beyond the tire issue. It's a first indicator that they may have a stability problem."

Ford and Goodyear Tire & Rubber Co. officials criticized The Post's analysis, saying the number of accidents examined was too small to be meaningful, that the databases don't always accurately identify vehicles and that Explorers should not be compared with the entire universe of SUVs, which can range from two-seaters to behemoths.

The Post analysis of fatal crashes nationally from 1997 to 1999, and a much larger Florida database of fatal and nonfatal crashes for the same period, indicated:

-- Explorers equipped with Goodyears had a higher rate of tire-related accidents than other SUVs in the national fatal accident records, though the 2,000 accidents involved are so few that the difference could be a statistical fluke. But an analysis of 25,000 fatal and nonfatal SUV accidents with 83 blown tires in Florida shows that tire blowouts in Goodyear-equipped Explorers contributed to crashes at rates more than double those of other SUVs. (Explorers with Firestones crashed four times as often as other SUVs after tire failures.)

-- Explorers were no more likely than other SUVs to have brake problems, worn tires or most other equipment failures that contributed to an accident in Florida. However, no other make or model of SUV has a pattern of equipment failure related as strongly to accidents as the Explorer's tire blowouts. Using two different ways of measuring accident rates, the Explorer was either three or four times as likely as other SUVs to have a tire blowout contribute to an accident.

-- Explorer's higher fatality rate in blowout accidents may be related to rollovers. In 5,870 single-vehicle accidents, where rollovers are most clearly recorded in the Florida statistics, the Explorer was 13 percent more likely to roll than other compact SUVs, against which Ford likes to compare the Explorer's rollover record. The Explorer was 53 percent more likely than other compact SUVs to roll over when an equipment failure such as faulty brakes, bald tires or blowouts caused an accident. The national data showed that in the 187 blown-tire accidents that killed someone in the SUV, the Explorer rolled over 95 percent of the time, compared with 83 percent for other SUVs.

The analysis also found the vast majority of the tire problems contributing to accidents happened after the vehicle had been on the road for three or four years.

Though tire blowouts are rarely the cause of accidents -- and Florida's climate is warmer, so its blowout rate may be higher than other states -- the differences The Post found in Florida between Explorers with Firestones or Goodyears and other SUVs is statistically "very, very significant," said Hans Joksch, a research scientist from the University of Michigan Transportation Research Institute.

"These are very simple, straightforward analyses that don't look at the fine points, but the results are so strong that it should lead to detailed study to what extent it's the tires, to what extent it's the Explorer, to the extent that it's Firestone and Goodyear," Joksch said. "The whole issue should be examined much more closely."

The number of tire-related accidents is small, but statisticians often compare incidences of rare events, said Paul J. Smith, a University of Maryland mathematician and statistician. "Statisticians use data on rare events all the time to make inferences on health statistics, crime rates, accidents and so forth," he said.

Ford spokesman Jon Harmon disagreed. "I think the Goodyear numbers there are an aberration," he said. "When you're cutting it this fine on things that are rare events, they're not always going to track."

Harmon said Ford compares Explorers with other SUVs over the entire decade of the 1990s, rather than the 1997-99 period The Post used. He said comparing Explorers to all SUVs is inappropriate. The Explorer is a compact SUV and that is what Ford compares it with. Using that standard, Explorers have lower fatality and rollover rates than comparable SUVs, he said.

"This (The Post) analysis absurdly penalizes Explorer for doing a better job at protecting its occupants in non-rollover accidents than its competition," Harmon said. "The Explorer is a safer vehicle than other compact SUVs, as shown year in and year out by the federal safety data."

James C. Whiteley, Goodyear's vice president for global product and process quality, said the company's extensive data on tires that were returned under warranty uncovered no meaningful difference between Explorers and other SUVs. The data show that tires on "Explorers are not the same, but not statistically different." He would not describe the difference, and said the company could not release the data because the information could be subject to misinterpretation.

"I'm not going to say there's anything wrong with Explorers," Whiteley said. "Explorers are Explorers. Jeeps are Jeeps. Our performance on all the vehicles has been very satisfactory. People have taken tires for granted. Tires are a highly engineered technical masterpiece, but people have to realize that tires fail. If you don't take care of a tire, we cannot make a tire that is indestructible."

He added that no one in Florida has sued Goodyear claiming that Explorer tires caused an accident there.
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With the Explorer one of the profit centers of the company, Ford's stake in defending its safety and performance is high. During recent congressional hearings on the tire recall, Bridgestone/Firestone Inc. officials tried to shift some of the blame to the carmaker for the more than 100 deaths and 400 injuries that federal regulators are investigating. Bridgstone/Firestone on Aug. 9 recalled 6.5 million 15-inch Firestone ATX and Wilderness AT tires, which were mostly on Explorers.

John Lampe, Firestone's executive vice president, said, "Tires will fail, and do so for a number or reasons. In most cases, a vehicle that experiences a tire failure can be brought safely under control. However, we have seen an alarming number of serious accidents from rollovers of the Explorer after a tire failure."

One reason, Lampe suggested, was Ford's advice to inflate Explorer tires to 26 pounds per square inch, lower than Firestone's recommendation of 30 pounds and lower than the pressure recommended for other popular SUVs. The 26-pound level left "little safety margin," Lampe said. Heat that can cause a failure builds up faster in a flatter tire carrying a heavy load in hot weather. (Ford said 26 psi is safe but recently accepted Firestone's recommendation and increased the suggested tire pressure to 30 psi.)

Sue Bailey, the National Highway Traffic Safety Administration administrator, told Congress, "I think we're dealing with a tire problem." But she added that as part of the agency's investigation, "we'll explore the possibility of a combination" of tire and vehicle problems causing the accidents. She said the Explorer is "part of the ongoing investigation because we are concerned about the rollover capability."

Ford has paid $4 million to settle 17 lawsuits triggered by Firestone-equipped Explorer crashes, the company told congressional committees. Firestone has paid $12 million to settle 14 cases.
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Government officials in Venezuela, where Ford replaced Firestone tires before the U.S. recall, have said Ford and Firestone share responsibility for the 47 deaths and dozens of accidents that have occurred there.

Samuel Ruh Rios, head of the Venezuelan consumer protection agency, said the accidents resulted from "a lethal combination" of the Explorer's design and certain Firestone tires. He said the accidents "have been caused by a macabre combination between a suspension that is set too soft and tires that are not appropriate for the Explorer."

According to a Ford document obtained by congressional investigators, the company's own analysis of rollovers after tire explosions in Venezuela found the problem unique to the Explorer.

The Venezuelan consumer agency also noted that when Ford began replacing Firestone tires in May, it offered to install stiffer shock absorbers. Ford said the offer was related to rough roads, not tire problems.

While not commenting directly on The Post's findings, Mehdi Ahmadian, director of Virginia Tech University's Advanced Vehicle Dynamics Laboratory, said that tires, axles and suspension are related. "The recent trend in the tire and automotive industry is to study the tire and the suspension as a combined module," he said. "The dynamics of one affects the other."

The rate of tire-related accidents was considerably higher on two-wheel-drive Explorers than on four-wheel-drive versions, The Post found. That matches a rollover analysis from the Highway Loss Data Institute, a research organization sponsored by insurers.

"Consistently, throughout the years, if you look at rollover issues, the two-wheel-drive is worse than the four-wheel-drive," said Kim Hazelbaker, the group's vice president. Because of their high center of gravity, SUVs have a higher rollover rate than passenger cars.

Hazelbaker said The Post's findings on Explorer rollovers after equipment failures indicate the Explorer "would seem to be a less forgiving design" and calls for study of vehicle dynamics that could explain the phenomena.

"I wouldn't jump to the conclusion that there was anything physically different about the vehicle that was causing that," Ford's Harmon said. "The two-wheel-drive may have a different driver population than the other driver population. That may explain the difference right there."

Prof. Ron Huston of the University of Cincinnati College of Engineering, who has testified as an expert in accident reconstruction and vehicle dynamics, said a vehicle that is more likely to roll over also would contribute to tire failures.

"These forces that are going to cause a vehicle to roll over are the forces that are going to cause dramatic force shifts on the tires," he said. "If it has a high propensity for rollover, it also has higher weight shifting on the tires."

SOURCE: By Dan Keating and Caroline E. Mayer / The Washington Post