Despite advances in tire technology, tread life is finite and will vary by car type, tire type (such as all-season or ultra-high-performance all-season), driving aggressiveness, and even road and weather conditions. You need to replace your tires a few times or more throughout the life of a typical vehicle. As the adage goes, nothing lasts forever.
Proper maintenance and responsible driving can maximize the mileage in a set of tires. Monthly tread inspections can inform when the tires warrant replacement, well in advance of the federally mandated treadwear indicators. And when it comes time to buy, you can use CR treadwear ratings to find tires that promise a long service life.
Before you buy new tires, check CR's exclusive ratings of tire stores.