For the most part, today's tires deliver more miles and years of service than ever before. In the 1970s, typical bias ply tires lasted less than 20,000 miles and were only expected to be in service for about two years. In the 1980s, early radial ply tires offered a tread wear expectancy of about 40,000 miles during four years of service. And by the turn of the century, many long-life radial tires extended treadwear to about 60,000 miles during four or more years of service.
While passenger car and light truck tire technology and American driving conditions in the past resulted in tire treads wearing out before the rest of the tire aged, it may not always be true of today's even longer lasting tires that are approaching 80,000 miles of tread wear.