Goodyear's Library-Like Labs Produce Hush-Toned Tires

ORLANDO, Fla., Feb. 5, 2004 -- They probably won't be confused with librarians, but Goodyear engineers such as Dave Griffin sometimes have the same goal as those working in the public book depositories -- "keep it quiet."

Griffin, development engineer, and his colleagues spend hours making sure Goodyear NAT is marketing the quietest possible tires.

One of those tires is the new Goodyear Assurance featuring ComforTred Technology(TM), a premium passenger tire that offers the ultimate in luxury and comfort. The new tire is available to consumers on March 1, and is targeted as a leading choice for the drivers of luxury cars, such as the Lincoln Town Car, Buick Park Avenue and Chrysler LHS.

For Goodyear engineers, computer analysis of tread drawings and the study of pressure-sensitive photography of a tire footprint are the first indications of its possible noise performance. Lateral grooves in the tread produce sound as the tire hits the road, and the repeating pattern of the tread design creates specific frequencies.

Therefore, one of the engineering tasks in tread design is to vary the geometry and distribution of the grooves to produce a wide range of noise frequencies. Variation of frequencies minimizes the chances that an annoying recurring tone will be produced.

"Obviously, we know that effective tread grooves are needed for wet traction, but we have to carefully evaluate their aggressiveness. Finding the right balance is a true science, as we consider the importance of low tire noise, while continuing to emphasize the product's stopping ability and maneuvering on rain-drenched roads," Griffin said.

A key to low-noise tire design success is engineering a product that makes no distinct sound without sacrificing other performance characteristics such as ride, handling and traction. For the Goodyear Assurance featuring ComforTred Technology tire, Griffin and other Goodyear engineers evaluated several tread patterns before selecting the best and quietest version.

One of Goodyear's high-tech advantages in the noise suppression effort is a unique room that is usually quieter than any public library. Because the sound quality of tires is determined inside the vehicle, Goodyear test personnel use the company's anechoic chamber, a room that suppresses echoes or reflections and allows tonal characteristics of noise to be evaluated.

The anechoic chamber is large enough to drive cars or even large trucks into, and an in-the-floor test wheel can spin the vehicle's tire with no need for the vehicle's engine to be running. This deletes any outside noise interference from the engine and other sources. Advanced measurement and analysis systems pinpoint the sounds emanating from the tire under evaluation.

As noise evaluation has moved from an art to a science, Goodyear's assortment of design and test tools, such as computer modeling and acoustical labs are facilitating predictions of how a tire will sound as it rolls down the highway.

"This creates an assurance for consumers that they're getting the best -- and quietest -- tire possible," Griffin said.