Autos must have tire pressure monitoring systems by 2008

WASHINGTON - A light on motorists' instrument panels will soon warn them when a tire is underinflated.

The safety regulation, issued by the government Thursday, has its roots in the Firestone tire recall of 2000. It requires new passenger cars to have tire pressure monitoring systems in place by the 2008 model year.

Automakers most likely will attach tiny sensors to each wheel that will signal if a tire falls 25 percent below the recommended inflation pressure. If any one of the four tires is underinflated, the sensor sets off a warning light.

Automakers will begin using the technology in September. The National Highway Traffic Safety Administration estimates the upgrade will cost between $48.44 and $69.89 per vehicle.

The government said underinflated tires affect a vehicle's fuel economy and can increase stopping distances, contribute to tire failure and lead to skidding on wet surfaces. One NHTSA survey found about 30 percent of cars and light trucks have at least one tire underinflated by 8 pounds per square inch or more.

The regulation was proposed last September. Tire manufacturers have questioned whether the warning system would signal low pressure early enough. Automakers have raised concerns that motorists may ignore the lights if they appear too frequently.

Congress, aiming to prevent SUV rollovers after the massive Firestone tire recall began in August 2000, sought the warning devices in the Transportation Recall Enhancement, Accountability and Documentation Act.