Tire Technology Still Requires Good Old Fashioned Testing

COSTA MESA, Calif., April 23 -- There are an estimated 21 million drivers today who own a vehicle with a Tire Pressure Monitoring System (or TPMS) -- a technological device designed to notify drivers of dangerously low tire pressure -- according to a recent study by NADAguides.com (http://www.nadaguides.com/). The company, a vehicle pricing and buying guide website, says that while these systems might provide drivers with added peace of mind, they don't provide enough information to let drivers achieve optimum handling or fuel efficiency, making checking tire pressure the good old fashioned way still important for car safety.

According to the study, tire pressure monitoring systems vary among vehicles, with two primary types -- one that provides only a general safety warning when tire pressure is low, usually with a light on the dashboard, and another that uses a more sophisticated system with numerical tire pressure readings linked to each of the vehicle's tires. NADAguides.com found that roughly 85 percent of 2008 model year vehicles use the basic system, while approximately 15 percent use the more sophisticated system.

The advanced systems arguably give the driver more information at his fingertips. However, the Federal Standard for all TPMS requires a safety warning only when tire pressure has dropped 25 percent below the manufacturer's recommended cold tire pressure. This means the driver of a car with a commonly recommended tire pressure of 35 pounds per square inch (PSI) would be warned when tire pressure drops to about 26 PSI. Research shows, however, that even a slight drop in PSI can compromise a vehicle's handling and safety, especially when it's loaded with passengers or cargo.

What's more, less-than-optimal tire pressure means less-than-optimal fuel economy. A drop of six PSI, for example, translates into a 10 percent decline in fuel economy, even though it often wouldn't trigger a TPMS warning.

"Low tire pressure negatively impacts fuel economy," said Tara Baukus Mello, senior writer and lead market analyst at NADAguides.com. "However, in this particular scenario, the only time a driver would know would be at the gas pump which isn't soon enough for many people, especially when Americans are projected to be spending 61 cents more per gallon on average this summer."

TPMS first appeared on passenger vehicles about ten years ago, with approximately 21 million vehicles on the road today equipped with some type of system. Certain earlier types of systems -- those on 2005 model year vehicles or older -- had accuracy issues or caused air to leak from the tires.

According to Baukus Mello, systems improved in 2006 when they became more sophisticated as a result of a federal standard that began to be phased in to bolster car safety. About 70 percent of 2007 model year vehicles came equipped with TPMS, with all passenger vehicles being required to have these systems for 2008 and beyond.

Baukus Mello says that while today's TPMS will warn you of significantly low tire pressure that could lead to a blowout or an accident, it's not the finest solution -- nor the only one -- for ensuring optimal vehicle handling and fuel efficiency.

"A driver's best tire safety resource is manual monitoring, the good old fashioned way," said Mello. "A monthly visual inspection of your tires coupled with the use of a tire gauge -- preferably digital versions as these are the most accurate to check pressure -- remain the best ways to make certain your car, truck or SUV is operating safely and economically."

About NADAguides.com

N.A.D.A. Appraisal Guides (NADAguides.com) is the world's largest publisher of vehicle pricing and specification information for new and used cars, trucks, vans, and SUVs, as well as van conversions, limousines, classic and collectible cars, boats, RVs, motorcycles, snowmobiles, personal watercraft and manufactured housing. The company's consumer website, NADAguides.com (http://www.nadaguides.com/), offers a variety of new and used vehicle services in addition to valuation information. Throughout its 75-year history, N.A.D.A. Appraisal Guides has earned the reputation as the recognized authority for vehicle valuations. Its website, NADAguides.com, is the most comprehensive vehicle information resource on the Internet today.