at 7 years you are at that point to look at replacing them. the best I have ever got is 10 years before a blow out, but most of the time its between 5 to 8 years for me. there are options other than good year endurance, personaly I wouldnt spend the money on them. several are going with somthing like a sailun S637-st tire, and running it at 80 psi, unless your rims will handel more. myself, I just went with a good no name tire this time and in 5 years I am chaning to the sailun as I didn't have the time to wait for them to come in as no one stocks them up here. So I went with a chinese I guess, but I went with a higher ply rating than the ones that came with the rv, so that gives a stronger tire. in my case I went from a 10 ply to a 12 ply. so it is a stronger tire than can handel more weight.