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Automakers Push For Tire Sensors

September 26, 2000

DETROIT (AP) _ While most modern cars and trucks have electronic sensors to detect everything from oil quality to changes in vehicle direction, checking the air pressure in tires remains a manual chore.

But in the wake of the uproar over recalled Firestone tires, automakers are researching ways to add tire pressure monitoring systems. A few already sell models with a basic monitor that warns if pressure falls too low.

Others, including Ford Motor Co. and DaimlerChrysler AG, are testing a system that would automatically keep tires inflated to a certain pressure and alert drivers to a slow leak. Suppliers say they’re getting more calls for such devices, as automakers try to answer what appears to be a newfound awareness of tire problems among consumers.

``The technology’s there, and it’s relatively cheap,″ said David Champion, director of automotive testing for Consumers Union, the nonprofit publisher of Consumer Reports magazine. ``I think to have a pressure sensor that warns you when tire pressures are low...that would be a great benefit to consumers.″

Tire pressure has become a focal point in the debate over Firestone tire failures linked to 101 deaths and 400 injuries. Critics have accused Ford of setting the tire pressure for the Firestones used on the Explorer sport utility vehicle too low, especially given that tires often run a few pounds per square inch lower than recommended.

Ford President and CEO Jacques Nasser has promised Congress that the automaker would speed up development work on tire sensor systems. The only system Ford sells now is a $640 option on Lincoln Continental sedans equipped with run-flat tires.

GM has installed a basic tire pressure monitor on about 1.6 million vehicles since 1997. The system uses the vehicles’ antilock brake sensors to detect changes in the shape of the tire, and sets off an alert if pressure falls below a certain level.

Auto parts maker Continental Teves has designed a similar system that will go into production in 2002, company spokesman Jim Gill said. He said interest in the system had picked up since the Firestone recall.

But Champion said Consumers Union tests of the GM system found it to be not sensitive enough to pressure changes. In the tests, Champion said the tire pressure had to drop below 20 pounds per square inch before the system set off an alert.

A more advanced system in some luxury cars, including the Chevrolet Corvette and the Plymouth Prowler uses a monitor installed inside the wheel hub to more precisely measure pressure.

GM spokesman Terry Rhadigan said the company is considering using tire sensors in more models, but declined to give specifics.

The system that Ford and DaimlerChrysler are testing would automatically keep tires at a level pressure. The system’s developer, Cycloid Co., already sells a similar device for semi trucks.

Cycloid’s AutoPump is a hockey puck-sized device that mounts on a wheel hub under the hubcap. It keeps tires inflated to a preset level through a compressor powered by the motion of the wheel.

Grant Renier, Cycloid’s chairman and CEO, said Ford and DaimlerChrysler were planning to use the company’s AutoPump on upcoming models. He said several other automakers and tire makers had contacted the company since the Firestone recall.

Renier said the AutoPump could also predict a tire failure based on how much air was being replaced. That information could be given to a driver as a warning that a tire would fail within a few hundred miles. Or if a vehicle had a built-in cellular connection, the device could send a signal that would contact a service station, which would dial the driver back and offer help.

It’s not clear whether any such system would have helped the people injured or killed in wrecks caused by Firestone tire failures. While the tire industry contends that underinflation causes a raft of problems with tires _ and might have played a role in the Firestone failures _ none of the systems in production or under development could monitor the tire’s structural conditions, such as how much heat has built up.

And such systems add cost at a time when automakers are looking to slash costs. Alan Baum, an analyst with IRN Inc., said such systems would likely be seen as standard features on luxury models.

``This is clearly something that has some value in the eyes of the consumer,″ he said.