Ford, which has had its share of about tire safety problems, is urging consumers to replace their tires after six years. Tires degrade even when they're not in use, the company says, echoing the claims of safety advocates who have been pressing federal regulators to take action on the issue.
The tire industry disagrees and says that tires are safe as long as the tread depth is a minimum of 1/16th of an inch, no matter what the age, and as long as there are no visible cuts, signs of uneven wear, bulges or excessive cracking. Other trouble signs are if tires create vibration or excessive noise.
SRS Inc., an auto safety research firm, last year petitioned the National Highway Traffic Safety Administration (NHTSA) to require easily readable creation dates on car and truck tires.
SRS President Sean Kane said that as of November of 2004, his group has documented 37 fatalities and 35 serious injuries associated with age-related tire tread separations. In many of these cases, the tires were unused spares and showed no signs of degradation.
Aged tires are often unsuspectingly put into service after having served as a spare, being stored in garages or warehouses, or simply used on a vehicle that is infrequently driven. In many instances these tires show no visible sign of deterioration, and absent any visible indicators, tires with adequate tread depth are likely to be put into service regardless of age, SRS said in its petition.
Kane's petition noted that environmental conditions like exposure to sunlight and coastal climates, as well as poor storage and infrequent use accelerate the aging process.
The British Rubber Manufacturers recommends that used tires should not be put into service if they are over six years old and that all tires should be replaced 10 years from their date of their manufacture but the U.S. Rubber Manufacturers Association derides the notion.
"Tires are not milk," Rubber Manufacturers spokesman Daniel Zielinski told the Wall Street Journal. But Zielinski's quip notwithstanding, many European car makers as well as Japan's Toyota Motor Corp. have long warned drivers that tires are perishable and many use six years as the cut-off point.
DaimlerChrysler's Mercedes division also tells drivers that tires last only six years and Chrysler now includes a similar warning in its owners manuals.
General Motors so far is a hold-out. A company spokesman says it hasn't found any research that supports six years as the deadline for replacing tires.
Ford's new position reflects its increased emphasis on tire safety following the disastrous series of rollover accidents afflicting its Ford Explorer SUV and other vehicles. Ford blamed the problem on Firestone tires and is still fighting hundreds of wrongful death and personal injury lawsuits arising from the series of deadly accidents that led to a massive recall.
The age of a tire already appesrs on the widewall but it's part of a lengthy code that can be hard to decipher. To find the age of your tires, look for the letters DOT on the widewall. That's followed by a 12-character serial number made up of numbers and letters, followed by four digits that identify the week and year the tire was made. For example, 2403 would be the 24th week of 2003.
