Ughh... I just went through all of this. I blew a 2 year old Carlisle "Radial Trail RH" 215-75R14 tire with little more than 3K on it. Always keep them at max pressure. This was after two had flats, and when Discount Tire was removing them all, they found another was ready to blow due to tread separation. Seems that they were not all very new when I got the set in Kingman in 2014. Two were pretty new (2114) and the other three were (3113) dated.
Darn thing took my fender with it, and some clown drove over the fender for no reason on the highway while I was walking back to get it. Everyone else missed it, as it was on the centerline!!!
Well, after talking ad nauseam to many people who are both in the tire business and the trailer business, this is what I learned:
1. LT tires usually have better tread and will resist punctures and heat better IF they are rated for the load you need to carry. Sadly, the only 14" LT tires out there are General Grabbers (LT8.5/70.14) but only had a 1,520 lb weight rating. The ST's that are closest in size are 1,870 lbs. I couldn't even go to 15's because my axles are too close together. Wheel well was no problem. Something to think about if you are considering a larger rim and don't have one of the newer spread axle trailers.
2. LT's are generally just as susceptible to sidewall puncture as ST's. "generally" Because some are designed to protect the sidewall, BUT you more than likely will NOT find them in something to fit your trailer without heavy mods.
3. Contrary to what's posted here, many ST tires are now rated at higher speeds than 65. Sadly, the Maxis tires are still 65, so that eliminated getting those for me, as our highways are 75 here...
4. Carlisle now has a "Radial Trail HD" rated tire. It was twice the price, beefier sidewall and tread. Got a set and hope they hold up. They are C load rated (1,870 Lbs) also speed rated to 79 MPH (Per Discount Tire) They supposedly now have a D load rated one in a 205/75 @65 PSI, but I was not offered that at Discount Tire, however, it is on Carlisle's website. Wish I knew about it last week. Maybe I can get them swapped. My trailer originally had 205's and the upsize was for more load capacity.
I'll report back as these age. I only expect 2 years out of them, but I will be pleasantly surprised If they go three. They do look better, as in more durable...
Info about Radial Trail HD tires.