Tire Technology On A Roll


Although we may take them for granted, radial tires introduced in 1974 revolutionized the tire and the driving experience. Recently, the evolution of the tire has hit another high point. Technological breakthroughs include tires that will run “flat” and systems that will alert drivers to low tire pressure.

AAA repair experts observe that more than 25 percent of the passenger cars and trucks they inspect have at least one tire 20 percent low in pressure. Not only does improper tire inflation reduce fuel mileage, it diminishes vehicle handling and makes a tire run hotter, making it more likely to fail.

Last year, AAA responded to 2.4 million roadside service calls to help members with flat tires. Tire-pressure monitoring systems and self- or auxiliary-supported tire systems could make these safety concerns and tire crisis situations obsolete.

Tire Pressure Monitoring 

Tire pressure sensors keep track of the correct air pressure and let you know with a warning light or similar signal that one or more tires has dropped below safe levels.

There are two kinds of tire pressure monitoring systems: indirect and direct. The inexpensive, indirect monitoring system uses wheel speed sensors on a vehicle’s anti-lock brake system to keep track of each tire’s rotation. An under-inflated tire has a smaller radius and therefore spins faster.When the wheel speed sensors detect a faster rotation, it alerts the driver. The downside is since wheel speed sensors rely on the rotational speed of the wheels, they may not be able to detect sight changes.

Direct tire-pressure monitoring systems rely on actual pressure sensors installed in all four tires. These accurately measure the pressure in each tire and send readings over air waves to a wireless receiver mounted in the car. Drivers are alerted to the specific tire that needs attention. Direct tire-pressure sensors are more accurate, more informative and more expensive.

The National Highway Traffic Safety Administration has mandated all 2004 vehicles sold in the United States should be equipped with devices that monitor tire pressure.

Self-Supporting Tires

Self-supporting tires, often known as “run-flat” tires, have a steel belt built in their sidewall that keeps them from collapsing even in a high-speed blowout. Michelin’s “zero pressure” tire and Goodyear’s “extended mobility technology” tire were first on the scene in the mid-1990’s.

The stiff construction of these tires is capable of temporarily carrying the weight of the vehicle even after the tire has lost all air pressure. The airless tire will continue to perform at speeds of up to 55 mph for 50 miles or more, keeping a vehicle mobile so the driver can get to a safe place for repairs.

The self-supporting design is so effective that a pressure monitoring system must be used to alert drivers when a tire is losing air. Without it, drivers may inadvertently put themselves at risk by driving beyond the safety limits of the run-flat tire.At some point soon, tires requiring air may even be old-fashioned. The concept of molding solid tires out of foamy urethane is being explored.