The model names of the recalled tires are ATX, ATX II and Wilderness AT, all for 15-inch wheels, with a size designation that is P235/75R15. All such ATX and ATX II tires are being recalled, but only those Wilderness AT tires that also have a Transportation Department 10-digit designation starting with the letters VD are being recalled.
For reasons that the company could not explain, the Wilderness tires made in Decatur, Ill. -- the ones designated VD -- seemed prone to failure, along with ATX and ATX II tires made in a variety of plants.
''We have not identified any manufacturing or design defect,'' Gary B. Crigger, executive vice president of the company, said at a news conference. ''We're pulling this size now, rather than try to figure out what the answer is,'' he said, and the company has not had time to ''do the forensics'' on tires in accidents.
Experts agreed, though, on the likely mechanism for the failure: heat, generated by tire sidewalls that flex excessively because there is too little air in the tire or too much weight on the vehicle. The problem is probably worsened by hot pavement and air temperatures, according to company officials and others.
Ford said today that it became aware of the problem a year ago, with ''anecdotal reports'' from Saudi Arabia, where drivers let air out of the tires to drive on the desert, then returned to paved roads and drove at high speeds without reinflating the tires. Ford has offered free replacements in several countries with hot climates.
Bridgestone/Firestone, which is the United States unit of the Bridgestone Corporation of Japan, acted in this country today after extensive discussions with the National Highway Traffic Safety Administration and Ford.
Bridgestone would not disclose the cost of the recall.
The deputy head of the safety administration, Rosalyn G. Millman, said in a statement that she was pleased that Firestone ''has taken a positive step toward resolving this safety issue.'' But a spokesman for the agency, Rae Tyson, said that its investigation had begun only in May and that the agency did not know enough now to order a recall.
Mr. Tyson said that the agency had begun its inquiry primarily because of an increasing number of complaints from consumers and that in recent days, as news reports cited the failures, the number of complaints rose sharply. The number of deaths being investigated as part of the agency's inquiry increased to 46 from 21 in the last week.
''I don't think anyone would want us to jump to any conclusions based on an investigation that just began,'' Mr. Tyson said. A crucial question for investigators looking into cases in which vehicles rolled over and had damaged tires is whether the tires were the cause, he said.
But some critics said the government response had been slow.
The safety agency has had weak leadership and has been preoccupied with other issues, including faulty rear-door latches on minivans, and sidesaddle gas tanks on pickups, said Joan Claybrook, a former administrator of the highway safety agency and now director of Public Citizen, the consumer rights group.
Ms. Claybrook said the companies had also been derelict. ''The first lawsuits they settled were back in 1992, and they've known about this for years,'' she said.
''They settled them with gag orders,'' she added. ''This has been a big cover-up for years.''
Mr. Crigger of Firestone said the company was facing 50 lawsuits. Asked whether secrecy clauses in the settlement agreements were intended to cover up the problem, Mr. Crigger said, ''I don't know about the status'' of such clauses.
In some suits, one question is whether the vehicles' suspension, which Ford designed, is partly responsible.
Ms. Claybrook said that the failures echoed a problem with tread on Firestone 500 tires that arose in 1978, when she was the administrator of the safety agency. That case, which also involved a large recall, was a severe financial blow to Firestone and was one reason it was acquired in 1988 by Bridgestone.
Of the tires affected by the announcement today, about two-thirds came new on Ford Explorer sport utility vehicles and Ranger and F-150 pickup trucks, Mercury Mountaineer sport utilities, as well as Mazda Navajo and B-series pickups. All were produced between 1991 and 2000. But millions of other tires were sold as replacements on other makes of vehicles. General Motors and Subaru, two other manufacturers that use Firestone for original equipment tires, said they had not had any reports of problems.
The problem, in fact, may be related in part to the vehicle, although statistics were sketchy today.
Explorers may predominate among the accidents because the vehicle is so popular. In addition, a tire failure in an Explorer may be a bigger problem than in other vehicles, said David A. Champion, the director of auto testing for Consumer Reports magazine.
''S.U.V.'s are more prone to roll over than other classes of vehicles because of the high center of gravity,'' he said. Thus a tire failure that causes an accident ''can be more dramatic'' in a sport utility vehicle.
Ford said it still stood by its longtime supplier -- Henry Ford and Harvey Firestone were close friends and business associates nearly a century ago. But today, the tire maker and the carmaker gave slightly different advice to owners of Explorers that have the tires. Ford said the tires should be inflated to 26 to 30 pounds per square inch, and Firestone said 30. And though Ford first heard reports of a problem a year ago, a top Ford executive complained today that it had taken until late last month for Firestone to turn over data on its warranty experience with the tires provided on new Fords. (Manufacturers use warranty complaints to track defects, but tire warranties are customarily separate from vehicle warranties.)
Ford said it requested the data from Firestone amid growing concerns about information accumulating in the investigation by the highway safety agency. ''It's only fairly recently that we had enough data to do detailed analysis,'' said Martin Inglis, Ford's vice president for North American automotive operations.
He vowed that this would change. ''Whether they warrant the tires or we warrant the tires, we will share the information,'' he said.
Jon Harmon, a Ford spokesman, said that when Ford learned of the problems overseas, it bought some Wilderness tires from American customers who had driven them 30,000 to 40,000 miles, giving them new tires in exchange. Ford engineers then drove them in Arizona in February, trying to duplicate the tire failures, but they did not fail. Ford concluded that the tires were fine and that the problem lay in how the tires were used overseas, particularly in Saudi Arabia, Mr. Harmon said.
Mr. Inglis said Ford had asked every tire manufacturer in the world if it could supply some of the tires needed to replace the ones being recalled.
Tires were moving briskly today. In Jacksonville, Fla., Dennis Perkins, parts manager at Mike Davidson Ford, hustled to secure tires in anticipation of an onslaught of customers. He said he called a Goodyear warehouse at 1 p.m. and was told it had 5,000 Wrangler RTS tires, a potential substitute, in stock. When he called back at 1:45 p.m. all 5,000 were gone.
In Lubbock, Tex., ''I have had at least 40 calls today,'' said Judy Stanley, the telephone operator at Gene Messer Ford. ''Their first question is, 'What am I going to do?' They are worried.'' She added: ''I give them the 800 number to Firestone. I don't know where it's going from there.'' (Firestone said today that its 800 number was jammed.)
At Manhattan Ford, at 787 11th Avenue near 55th Street, Steve Huang drove up in a midnight-blue Mercury Mountaineer that he had bought there last week, complete with Firestone AT Wilderness tires. He reacted indifferently to the news.
''Recalls happen, and they are usually handled responsibly,'' said Mr. Huang, who sells surveillance cameras. ''I'm not worried. This is a great car, and it handles great.''Continue reading the main story