I came on here because the net heading on this site said that all Hercules tires are made in China. Who ever posted that is full of it.
Cooper Tire makes them. They are one of only TWO U.S. owned tire companies that exist today. (Firestone was bought out by the Japanese company Bridgestone back in the 1980's.
They also make tires here in the U.S., but are Japanese owned. I know because I built their tire machines at two different U.S. plants.) I have Hercules tires on a Dodge Challenger (V rated, for those who understand what that means.) and they preform very well. Tire dry rot is normal on vehicle that is parked and sits on soil and grass and not used often.
Different soils have different PH (acid) values. (Don't say NO... that's not it. Or that wouldn't cause it, because I had a 4.0 in chemistry and own a small farm where I have to do soil tests before planting to insure I have the proper PH levels for what I am planting.
This explanation would account for your tire rot.
Try parking your truck on concrete blocks. That should help with the problem.
Product or Service Mentioned: Hercules Tires Tires.
Reason of review: Good quality.
I liked: Performance, Value.