With two simple sentences, Ford Motor Co. likely has caused the blood pressure of every executive in the tire industry to rise.
``Tires degrade over time, even when they are not being used. It is recommended that tires generally be replaced after six years of normal service.''
Ford unceremoniously slipped that paragraph about tire age recently into its owners' manuals and onto its Web site, despite the insistence of the tire industry that there are too many variables in tire aging to set a hard-and-fast expiration date.
Furthermore, a DaimlerChrysler A.G. spokeswoman said her company will add the same advice to its owners' manuals beginning with the 2006 model year. She said DaimlerChrysler decided to take that action after discussing the issue with a number of tire manufacturers, which she declined to name.
This claim brought disbelief from a spokesman for the Rubber Manufacturers Association (RMA), who said that no tire maker would have told DaimlerChrysler a six-year shelf-life recommendation was a good idea.
``I can't imagine that happening,'' the RMA spokesman said. ``It doesn't make any sense. Ford has never shared any (tire aging) data with us that we know of, and the same with DaimlerChrysler.''
The two auto manufacturers' recommendations fly directly in the face of tire industry wisdom, which states that storage and maintenance have more to do with a tire's degradation than chronological age.
However, General Motors Corp. won't join Ford and DaimlerChrysler in recommending to customers that they change their tires after six years, regardless of treadwear or other factors.
``The fact is that most tires wear out before they age out,'' said James Gutting, director of GM's Tire and Wheel Laboratory in Milford, Mich., in a prepared statement. The auto maker said it requires its tire suppliers to meet more than 20 critical performance specifications, including passing an accelerated tire aging test.
While motorists should be mindful of high temperatures, high speed and heavy loads when considering tire replacement, GM doesn't recommend automatic replacement after a certain number of years if those factors are no more than normal, the company said.
``I would rather have a properly stored 6-year-old tire than an improperly stored 1-year-old tire,'' said Tom Cadotte, vice president of marketing for Flynn's Tire Co., a Mercer, Pa.-based tire store chain with 17 outlets in Pennsylvania and Ohio.
Mr. Cadotte knows the tire industry from both the retail and manufacturing sides. Before joining Flynn's, he retired from Goodyear's Kelly-Springfield Tire Co. operation as vice president of marketing for consumer products. He said he dreads the periodic stories on news broadcasts that in essence tell consumers their tires are ticking time bombs.
``After one of those news stories, if you show customers a tire that's been stored four or five years, they'll throw up their hands and say, `Oh no, that's too old! I don't want that!''' Mr. Cadotte said. ``Retailers try to turn over their stock, but some unusual sizes can stay on the shelf that long. If news programs would tell consumers how to check for underinflation, worn treads and cracking, they'd be doing a public service.
``It's not like there's nothing to tire aging,'' he added. ``You don't want to buy a 10-year-old tire. But I wouldn't take a 6-year-old tire off a car just because of its age. To read the serial number and take a perfectly good tire off a car is just wrong.''
However, positions such as Mr. Cadotte's are becoming increasingly embattled. For the past two years, Sean Kane, president of safety activist group Safety Research & Strategies Inc., has pressed the National Highway Traffic Safety Administration (NHTSA) to establish expiration dates for tires.
NHTSA is studying the effects of tire aging and hopes to add a tire aging test to federal tire safety standards perhaps as early as this summer.
The tire industry had to beat back an effort early in 2004 by Sen. Mike DeWine, R-Ohio, to include a tire expiration date provision in a larger motor safety bill. A bill to require tire manufacturers to mold non-code dates of manufacture on both sidewalls was introduced this year in the New York legislature.
Mr. Kane said he was encouraged by Ford's decision to recommend tire replacement after six years and pleasantly surprised by DaimlerChrysler's decision to follow suit.
``Ford's announcement carries a tremendous amount of weight, considering the work they've done already in studying the effects of tire aging,'' he said. ``This will have an effect not just among vehicle manufacturers, but also within the tire industry and at NHTSA, which is following Ford's lead in tire aging research.''
Mr. Kane said he would soon file an addendum to his original petition to NHTSA regarding accident rates among vehicles with aged tires. According to him, aged tires so far have been responsible for 70 highway accidents that caused 52 deaths and more than 50 serious injuries. He told Tire Business he gleans his accident data from a survey of litigation in which the tires in question are six years old or older, have ample tread depth and have no other obvious problems.
A Ford spokesman confirmed that the company based its decision on its ongoing research in tire aging. John M. Baldwin, the Ford polymer science technical specialist who heads the company's tire aging research, could not be reached for comment, but in a speech he gave at the Clemson Tire Industry Conference in March 2004, Mr. Baldwin said that aging is a crucial element in tire degradation.
This fact became apparent in Ford's study of the Firestone Wilderness AT tires, which were recalled in August 2000 as part of a massive recall effort by Bridgestone/Firestone. Those P-metric light truck tires were standard equipment on Ford Explorers and other Ford sport-utility vehicles, Mr. Baldwin said at the conference.
``If you look at the first two years of service for those tires, there essentially were no reports of failure,'' he said. ``It took two years for something to happen. Then, when you look at two vs. four years of service, peel strength had dropped 50 to 75 percent in the field. Obviously, the rubber's changing.''
Meanwhile, Mr. Kane has sent letters to Ford, DaimlerChrysler and the Alliance of Automobile Manufacturers (AAM), requesting their support for a NHTSA consumer advisory on aged tires. Such an advisory, he said, would be seen by many more people than a note in owners' manuals and could well become a guideline for tire dealers and technicians.
A spokesman for the AAM said his organization takes no position on tire aging.
Mr. Kane said GM Europe advises its customers to replace tires after six years, as do other auto makers such as Toyota Motor North America.
However, the RMA spokesman said that of its tire manufacturer members he had contacted, none said they had spoken with DaimlerChrysler on the subject of tire aging.
The Ford and DaimlerChrysler recommendations are only ``useless rhetoric,'' according to an executive with a large tire wholesaler who asked to remain anonymous.
``Vehicle owners don't follow what's in the owner's manual anyway,'' he said. ``When was the last time you read your owner's manual? My guess is that very few motorists will even read the advice to change their tires every six years-and that even fewer will comply with it.''
Asked about the average or maximum time a tire might stay in his company's warehouse, he said, ``That's all over the ballpark. All I can say is that it's absolutely no longer than we have to. We're staying up nights trying to make it zero because inventory is costly.''
If the Ford and DaimlerChrysler advisories become common practice among motorists, tire manufacturers will have to lead the industry to address the situation, according to Ron Sinclair, vice president of marketing for American Tire Distributors Holdings Inc. (ATD).
``The distribution model in the industry is manufacturers to distributors to retailers,'' Mr. Sinclair said. ``All constituents would have to be involved in putting a plan together.''
There would have to be some sort of tracking system, probably including clear marking and labeling of tires, he said, adding that no such system exists in the industry today.
ATD strives to turn over its inventory in 60 to 90 days, depending on the brand and category of tire involved. ``But again, you have to remember there are three steps to the distribution system,'' he said. ``Our question would be, `What's the age of a tire when we receive it?' I don't have any statistics on that, because we just don't track that.''