The last 2 sets of tires I had on my 1994 Dodge 2500 were Coopers and I loved them. The AT3's were fantastic for me and they had a lot of tread left when I sold the truck and the tires had 30,000 miles on them. I got 60,000 miles out of my first set of Coopers.
I have Toyo Open Country AT tires on my new truck as thats what was on it when I bought it and so far they are great as well.
I would not be afraid to buy another set of Coopers
