The federal government has turned down the tire industry's petition for a tire pressure reserve load requirement, ruling the industry did not prove its case for a standard the government considers prohibitively expensive.
There are no data, either from the tire industry or the government, that show any conclusive relationship between tire pressure reserve and tire failure claims, the National Highway Traffic Safety Administration (NHTSA) said. It issued a document May 19 rejecting the July 2002 petition from the Rubber Manufacturers Association (RMA) requesting a tire reserve load standard.
This marks the second time in a little more than a month that NHTSA has disappointed the tire industry. On April 7, the agency issued a final rule on tire pressure monitoring systems (TPMS) that retained the provision allowing tires to fall to 25 percent below the vehicle manufacturer's recommended air pressure before the monitoring system warned motorists.
The RMA and the Tire Industry Association (TIA) condemned the 25-percent differential. They insisted that tires would suffer serious damage long before falling 25 percent below the recommended inflation, and the lack of warning would give motorists a false sense of security about their tires.
It was precisely because of the 25-percent rule that the RMA petitioned NHTSA for the tire reserve load requirement.
``Many vehicles have tires mounted on them which...have little or no reserve to begin with and thus require more frequent pressure maintenance to ensure safe operating conditions,'' wrote RMA President Donald B. Shea in his original petition.
An RMA spokesman expressed his association's unhappiness with the NHTSA ruling. ``We feel there should be a reserve load requirement to prevent motorists from driving on underinflated, overloaded tires,'' he said.
The denial of the tire reserve load petition goes hand-in-glove with the TPMS rule, said Roy Littlefield, TIA executive vice president. ``TIA is frustrated with NHTSA's apparent lack of interest in what the tire industry has to say,'' he said.
In denying the RMA petition, NHTSA rejected the entire premise of the tire industry's argument.
``The agency does not anticipate that consumers will come to believe that tire maintenance is unnecessary unless and until the TPMS warning telltale is illuminated,'' NHTSA stated. ``The agency believes that sufficient measures are in place to ensure that TPMSs operate as a supplement to regular tire maintenance, not as a substitute for it.''
NHTSA said it was unconvinced that the RMA's figures correlating low tire pressure reserve with tire failures had any real-world basis, and added that its own data showed little connection between the two.
The RMA argued that any vehicle redesign required by a tire reserve load requirement could be stretched over several years and would be more than offset by the safety benefit. In its own analysis, however, NHTSA estimated that a tire reserve load rule would cost consumers and the auto industry $132 million annually, while saving maybe five lives a year.
Many vehicles would require a tire pressure increase of up to 8 psi to meet a reserve load standard, the agency added. This would mean either a significant decrease in ride comfort or major vehicle redesign to accommodate larger tires.
The tire industry has no recourse but to accept NHTSA's ruling, according to the RMA spokesman. ``The loop is closed,'' he said. ``This was a denial of a petition, not a rulemaking.''