ST Tires might get you 20 to 30,000 miles but thats not enough for me. I've been RVing for over 30 years and I would run nothing less than Michelin XPS RIB tires on my 41 foot 5ver. I have almost 60,000 miles on them and still have probably another 20,000 or so left on the tread. The good thing about these tires are they are re-groovable which means at least another 10,000 miles. They are 14 ply sidewall and made from the same rubber compound as over the road commercial truck tires. They are not cheap but after buying 3 sets of ST tires which might get you this kind of mileage combined you actually come out cheaper buying the Michelin tires. Thats just my opinion but if your gonna invest in a nice RV then don't go cheap on the tires that you depend on to get you where your going.