GM Statement Regarding Tire Aging

Attributable to Alan Adler, Product Safety Communications

General Motors engineers work with suppliers to develop tires specific to each GM vehicle’s needs and specifications. All tires must pass an extensive battery of qualifications that make up GM’s “Tire Performance Criteria.” This involves more than 20 critical performance specifications, including a test that accelerates a tire’s aging process.

“The fact is that most tires wear out before they age out,” said James Gutting, director of GM’s Tire and Wheel Laboratory in Milford, Mich.

When it comes to tire aging, GM specifically alerts customers to any unique case where excessive aging might occur before the tire wears out. The three main contributors to premature aging are high temperatures, high speed and heavy loads. Where nothing suggests aging to be excessive, we do not recommend replacing tires after a certain number of years.

“We recognize that tires do age, and we are participating in studies that are trying to get a better understanding of the issue.” Gutting said. “The customer operating environment for the main aging factors varies greatly, and that makes it difficult to select a specific age when tires should be replaced.”

GM recommends that consumers regularly inspect their tires, both those on their vehicle and any spares, for signs of wear or damage, specifically:

* Tread wear can be seen at three or more places around a tire * The cord or fabric is showing through the tire’s rubber * The tread or sidewall is cracked, cut or snagged deep enough to show cord or fabric * A tire has a bulge or split * A tire has a puncture, cut or other damage that can’t be repaired well because of the size or location of the damage