I replaced the first set of Billboards that had maybe 6,000 miles on them. The tread wear was marginal. The tread would probably have been good for another 20,000 miles.
It was the sidewall cracking from ozone deterioration, and many comments by other folks, that encouraged me to replace them. The tires were at least 8 years old when I replaced them. Take a good look at this shot of my old tire.
David
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