For what it's worth. My old Marathons lasted me 6 years trouble free. I replaced them mid trip due to an air leak in the sidewall of one of the tires. I replaced all due to their age and signs of drying out.
After I had posted pics of my blowout, others responded that it looks like I had encountered some type of road hazard that caused the tire to fail. The tire dealership that replaced the two tires hinted at the same cause.
I held on to the tires because I wanted to contact Goodyear. I did. This was their response.
Thank you for contacting our web site. We are always concerned when we
learn that we have failed to exceed a customer's expectations with regards
to our product or service.
All Goodyear tires come with a six year limited warranty. During the first
12 months or 2/32" of tread wear, whichever comes first, tires removed from
service due to a covered warranty condition will be replaced with a
comparable Goodyear product free of charge, mounting and balancing are
Tires not eligible for free replacement that are removed from service due
to a covered warranty condition will be replaced with a comparable new
Goodyear tire on a prorated basis for up to six (6) years from the date of
purchase. (Without proof of purchase the date of manufacture will be used
to determine eligibility.)
Without inspecting the tire in question we could not comment as to its
cause or condition.
Goodyear relies on a network of retail locations, both Company Owned and
Independent to determine warranty eligibility. If your tire is still
available and has not been inspected by an authorized Goodyear retailer we
would suggest you do so. You can locate your nearest authorized retailer
by calling toll free 1-800-466-3932 or on our web site at the following
If after inspecting your tires the authorized retailer is unable to assist
you please ask them to contact our Customer Assistance Center toll free at
1-800-321-2136 to discuss your situation with one of our Customer
Assistance Professionals. Please reference file number 1412625.
I decided not to argue the point after suspecting I indeed may have run something over. I took the tires to my local Costco to have the tires disposed of. I asked them to look at both tires and he pretty quickly came to the conclusion that it looked as though something had punctured the tire. Not so obvious on the one that was shredded, but on tire number 2.
I'll just have to have faith in the new ones seeing the originals lasted me 7 good seasons.