Annually, the auto industry receives about 100 million warranty claims, 13 million customer complaints and 9,000 property-damage claims. It writes up some 50,000 reports a year on field investigations into problems with vehicles and is involved in 10,000 product-liability cases.

This August, the makers of autos, tires and child car seats will have to turn over to federal safety regulators for the first time -- in response to the Firestone tire-failure debacle -- information such as this. Almost all of it, including numbers on death and injuries and annual production, is now closely guarded by the companies. And the prospect of sharing the data is a disconcerting one, even if it's just with the National Highway Traffic Safety Administration.

Even more unsettling for the companies involved is the prospect of seeing this data made public, whether on the agency's Web site, elsewhere on the Internet or shelved in the public reading room. NHTSA is in the midst of revising its confidentiality policy, so spirited discussions are going on about how much of this information should be made public, and under what circumstances.

The pending flood of data is mandated by the "early warning" provisions of the safety law Congress passed following its investigation of 271 deaths and hundreds of injuries after Bridgestone/Firestone tires suffered tread separations, most of them on Ford Motor Co.'s popular Explorer sport-utility vehicles. Last July, NHTSA issued a rule implementing those provisions.

In that case, critics contended that the companies had information on the tires' problems long before they shared it with the government. The agency, meanwhile, knew that deaths and injuries were occurring but said that it didn't have enough information to open an investigation before May 2000. As a result, Congress determined that manufacturers should be required to supply NHTSA with information about alleged problems with products much earlier.

The new rule stipulated that manufacturers had to supply early-warning data on a quarterly basis -- going back 10 years for the first report -- to the agency for every make and model of vehicle, covering 22 different types of components, such as steering and suspension systems, brakes, and engines. There are slightly different requirements for tire and child-seat makers.

The auto industry believes the submissions -- in their unfiltered form -- could create a connect-the-dots picture that would help competitors while possibly scaring away buyers and encouraging plaintiffs' attorneys. So they are trying to convince the agency that they would suffer competitive harm if the entire database were made public.

"It would be highly unfair to the U.S. auto industry to force it to give away its confidential quality and customer-satisfaction data. We know of no other industry . . . that is required to do that, and we believe it would be inconsistent with the federal Freedom of Information Act protection of confidential business information to do so," said Erika Z. Jones, outside counsel to the Alliance of Automobile Manufacturers, which represents the majority of domestic and foreign auto companies.

Instead, the auto companies hope NHTSA will decide to treat much of the data as confidential unless the agency opens an investigation into a specific defect. Industry officials view disclosure is those cases as less damaging because it is limited to a specific problem, make and model. They still can ask that the information remain confidential.

Furthermore, the industry would like NHTSA to create a special class of information that is automatically protected from peering eyes because it is "presumed to cause competitive harm." That would include aggregate numbers filed regarding warranty claims, consumer complaints, property-damage reports and the number of field reports. This would be in addition to information that the agency now routinely keeps confidential, such as blueprints and engineering drawings, future model plans, and future production or sales figures.

Tiremakers have their worries, too. In its filing with NHTSA, the Rubber Manufacturers Association said, "NHTSA has no legal authority to disclose industry-wide early warning data." In particular, tiremakers don't want production figures made public because they say it would tip off competitors to company marketing plans.

Safety advocates oppose the idea of trying to limit public disclosure of the data. They accuse the auto industry of trying to circumvent the idea behind the early-warning system. They want disclosure to be the norm unless business asks for confidentiality and the agency -- narrowly -- grants it. They would also like to see the data up on the Internet. "It should be put up as soon as it gets submitted," said Joan Claybrook, a former head of NHTSA who is now president of Public Citizen, a nonprofit consumer advocacy group.

Public Citizen also is urging NHTSA to create classes of information that are routinely made public, such as consumer complaints, deaths, injuries and lawsuits. In its confidentiality proposal, the agency suggested consumer complaints and other data might be routinely released.

The biggest question the agency has to answer before issuing new confidentiality rules in the next few months is what Congress had in mind for disclosure of early-warning data, officials said, and then how to balance the disclosure issues. "There are many people who want to see this information put up on the Web, and there are people who would like to see none of it up on the Web. We'll go through it and do the legal analysis and try to be as clear as we possibly can," said a NHTSA official. "But no matter what happens, somebody is not going to like it."