I asked both the tire barn and the goodyear store, which I do business with, they said the waranty is tread life or so many years, whichever comes first.
I was wrong on the years, I copied this from Goodyears web sight.
A tire has delivered its full original tread life and the coverage of this warranty ends when the treadwear indicators become visible (worn to 2/32 in. or .16 cm), or 6 years from the date of original tire manufacture, or new tire purchase date (whichever comes first). (Without proof of purchase, the date of manufacture will be used to determine eligibility).
You get 6 years from goodyear with proof of purchase.
So OLD, how old were your tires and what brand?