The National Highway Traffic Safety Administration's (NHTSA) tire pressure monitoring system rule has been thrown out by a United States Appeals Court.
NHTSA issued a regulation last year that mandated the placement of tire pressure monitoring systems in new vehicles starting with the 2004 model year.
Under that rule, tire pressure monitors had to warn drivers when tire pressure fell 25% or 30% below the vehicle manufacturer's recommended level.
NHTSA's rule only allowed for direct monitors.
"The court overturned the rule on grounds that the agency inappropriately permitted certain types of tire pressure monitoring systems to be installed on new vehicles," say Rubber Manufacturers Association (RMA) officials.
NHTSA's 25% and 30% thresholds "may not be good enough for all vehicles," according to an RMA spokesman.
The issue should be "for each vehicle, at what point will (a tire's) psi level be unacceptable under a maximum load?" he says.
The RMA estimates that 10% of 2004 model year vehicles will be outfitted with tire pressure monitoring systems and are already in the pipeline.
But the court has ordered NHTSA to completely reformulate the rule. "The standard by which a warning light comes on needs to be changed," says the RMA spokesman.
Last year the RMA asked NHTSA to adopt a new regulation that would require tires to have a reserve inflation pressure that would be sufficient to carry a vehicle's maximum load even if tires lost a large amount of pressure; NHTSA never responded.
NHTSA has appealed the court's decision. "We don't know what (the agency's) next step is going to be."
