DETROIT - Burned by the Firestone mess, Ford says it is putting in place new tire tests and no longer will take a tire manufacturer's word that its tires are safe.
Ford's newly assembled team of 100 engineers, for example, will test tires to the point of failure before approving them for a vehicle.
'We have a far greater knowledge of tires now than when we had in the mid-'90s. This knowledge could have helped us back then,' said Ford truck spokesman Jon Harmon. 'We just didn't do that kind of testing. That would be the tire maker's responsibility. We had all (the) expectations that the tire maker would do that.'
Here is one example of how Ford did not test as rigorously as some competitors: In 1995, Ford redesigned the suspension of the Explorer. Ford issued new specifications for the Firestone tires and relied on Firestone for safety tests.
GM, BMW and DaimlerChrysler say they would have tested the new tires to the point of failure.
Since late last year, Ford engineers have been conducting extensive tests on Firestone and other brands of tires by slicing them open and measuring individual parts. They also run the tires on special machines until they fail. Many of these tests will become standard.
Jason Vines, Ford's vice president of communications, said the company will use what it has learned in its high-tech testing and computer modeling to try to ensure that the tires it installs on its cars and trucks are safe.
'We'd be stupid not to, wouldn't we?' he said.
From in-house testing, Ford officials concluded that the 6.5 million Firestone tires replaced last year, as well as most other Firestone tires on its trucks and sport-utilities, run hotter than competing brands and might fail more often as they age.
Ford also says Firestone tire safety performance varies from one factory to another. In May, Ford said it lost confidence in Firestone's tires and recalled 13 million Firestone Wilderness tires at a cost of $2.1 billion.
The National Highway Traffic Safety Administration is investigating 203 deaths and 700 injuries in Ford light trucks, most of which were outfitted with Firestone tires.
Tire testing varies
At least two other automakers - GM and BMW - do not rely solely on the tire maker's safety and durability test data. GM and BMW verify tire durability with their own series of high-stress tests.
Tire safety and performance are critical at BMW, which has built its reputation on the high-performance handling of its vehicles. BMW engineers perform several durability and safety tests. They run tires on test cars to the point of failure. And tires must be able to withstand 20 high-speed laps on a racetrack and still have enough tread for street use. GM issues its own list of performance and safety specifications that tire manufacturers have to meet. GM engineers then subject the tires to a battery of endurance tests to ensure tires perform safely. If the tire passes, it is approved for the vehicle. Some of GM's durability testing is done in-house and some is outsourced.
In hindsight, the shortcomings in Ford's tire-testing procedures were underlined in 1995, when Ford redesigned the suspension in the Explorer and issued new specifications for the tire.
But Ford did not test the Explorer's new Firestones to the point of failure. It tested only for performance. Ford has decided that even though tire companies have the most experience carrying out intricate durability tests, it will test the limits of the tires it puts on its vehicles.
'A tire is a little different because it is branded (Firestone or Goodyear, for example) so prominently. And it's warranted differently. But customers expect safe tires, so the buck does stop with us,' Harmon said.
Most automakers do not provide the warranty for tires they install on their vehicles. Replacing faulty tires is usually the responsibility of the tire manufacturer. But Ford customers have been able to get their tires replaced under warranty at many of the company's dealers since 1999.
Although Ford didn't carry out durability testing on the tires used on the 1995 Explorer, Ford and Firestone say the changes to the suspension did not affect safety.
In an effort to improve the Explorer's handling, engineers in 1995 changed the front suspension from a truck-based Twin I-beam to a more car-like short-long arm system.
Ford's Vines said the revamped front suspension has nothing to do with Firestone tire failures, noting that most tread separations occur on the Explorer's rear tires.
He also cites company data from 1995 to 1997 when Ford equipped Explorers with roughly the same number of Firestone and Goodyear tires. Each brand of tire had identical performance specifications. Ford says it has documented 1,183 cases of tread separations on Firestone tires, compared with only two on Goodyear tires on 1995-97 Explorers.
'One did well, the other did miserably. We changed the suspension for the Goodyear tires as well. It's the Firestone tires. A thinking person cannot explain it any other way,' he said.
Lawyers fault suspension
Lawyers suing Ford say the Explorers most likely to flip over after a tread separation are two-door Sport models produced between 1995 and 2001. They say that because the new suspension system weighs less, the Explorer Sport's center of gravity is higher than it was before the suspension change.
Firestone spokeswoman Jill Bratina said the 1995 changes for performance were made to the bead area of the Explorer's Wilderness tire - where the tire meets the rim. Firestone reduced the weight of the tire in an effort to help boost the Explorer's fuel-economy ratings. But Firestone didn't test the revamped tire to the point of failure, Bratina said, because the changes didn't affect the tread or the safety of the tire. The full array of tire durability testing Ford will conduct in-house has not been decided, and no timetable has been set to implement it.
Said Harmon: 'We are going to work in conjunction with tire makers. We'll do testing. They'll do testing. We've helped advance the state of the art of tire testing, but it's on ongoing process.'