Starting in 2007, the government wants all vehicles to have warning lights that alert drivers to low tire pressure.
A proposal Wednesday would require that vehicles have a yellow light that would illuminate when the pressure on any one of the four tires was underinflated by 25 percent or more.
Federal regulators said the proposal probably would cost as much as $70 per vehicle, or a total of $1.1 billion annually, based on average sales of about 15.7 million new vehicles a year. But the requirement would save as much as $1.7 billion in fuel and vehicle maintenance costs, according to the National Highway Traffic Safety Administration.
Dan Zielinski, a spokesman for the Rubber Manufacturers Association, said tire makers disagree with setting a flat rate of 25 percent underinflation.
“For one vehicle that might be fine. For another, it might not be,” Zielinski said. “If you want to make a system that warns people, you should warn people before they’re in danger.”
Zielinski said automakers set their recommended pressure for a variety of reasons, including vehicle handling. That recommendation may be above the minimum needed to carry the vehicle at its maximum weight, so if the pressure drops, the vehicle will still be safe.
But if the pressure is right at the minimum, a 25 percent drop would mean that the tires could be damaged because they do not have enough air to carry a fully loaded vehicle, Zielinski said.
The agency said its testing indicates that vehicles can operate safely at the 25 percent figure.
The Alliance of Automobile Manufacturers, which represents 10 automakers, said 10 percent of vehicles already have tire pressure monitoring devices.
“We view this as a ratification of what the industry is already doing,” spokesman Eron Shosteck said.
In a nod to automakers, the government would require that the systems work when a vehicle is first sold but not when its tires are replaced. The agency agreed that automakers cannot make systems compatible with all of the possible replacement tires owners. But NHTSA said data indicates the systems work with the vast majority of replacement tires.
Congress ordered the agency to require tire pressure monitors as part of the federal response to the Firestone tire recall, which began in August 2000.
The agency in June of that year first issued a rule requiring warning lights. Safety groups sued, saying the rule was weak because automakers could choose between cheaper “indirect” monitors, which work off the antilock braking system, and more accurate “direct” systems, which have monitors in each wheel.
A federal court agreed with the safety groups and threw out that rule in 2003. The proposal released Wednesday does not specify what kind of technology automakers should use, but it does require all four wheels to be monitored.
The agency allows 60 days of comment before issuing a final rule.