So, I blew out another LT23585R16 Kumho load range E tire on the way home from BIR. In all fairness, they are 8 years old, with less than 3,000 miles. I've been nosing around for info, and it seems that opinion is:
Go for temp rating of A. Very few will declare any ratings.
If one blows, replace both on that side.
Go for LT tires over ST tires.
If using ST, keep speed to 65 or less.
I know I'll have more than one spare from this point on.
Opinions, experience's?

My experience has been to run your tires 10# over what the sidewall say's.

Since we all travel at speeds above 65MPH. I have been doing it on many different trailers in the last 25 years.

A tire store next door told me to do it a long time a ago. Then I see the tech bulletin from Goodyear a few years ago(they keep updating the date of it), it applys to all ST trailer tires not just goodyears tires IMO. It greatly reduces the chance of blowout being 10# over inflated no matter what speed you travel. That's my advise and experience. I've pulled a trailer over 13K miles this year already. More to come and have been for many summers now. I wear my trailer tires out, and luckily not blow them out.

Check this out to backup what I'm saying about over inflating, it helps a lot. Don't be afraid, over is way better than a little under pressure. And DO NOT run rubber valve stems on any trailer tire, screw in brass or steel only.

BTW I'm a goodyear ST trailer tire fan, I have had great luck with them over inflated.

If you continue to blow tires that are fresh and properly inflated, then I would look at your overall weight. Is your trailer over loaded? Ever weighed it? If not you should at just about any truck stop.
web page

I had a Load Range E tire like yours that was brand new and stored indoors for 6 or 7 years. When I finally used it, the tread peeled like a banana after less than 2,000 miles.
Luckily it stayed fully inflated and I drove for several more miles on the steel cords until I found a safe spot to pull off and change it! Age is a big factor.

I believe that keeping a trailer as level as possible is also important so one axle isn't loaded more than the other. Recalling the history of which axles had blowouts can offer a possible clue.

i wouldn't pull out of the driveway with an 8 year old tire, always run goodyear marathons and check air pressure before i leave out.

I have always had better luck with an LT tire than an ST many of the RV company's now put LTs on there new RV's. I believe this is mainly because of speed limits.

there's a discussion on this at forAbodies only too...

I buy trailer tires every two years. I live in he77... it's hot, dry, trailer sits outside with tires always covered, road temps can reach 140. Often I stop for fuel, rest, beer... and check the tire temps. They all run around 130 degrees. I run them at the max sidewall rating (these were E rated 95psi). Not sure I subsribe to that theory... as the heat will drive this psi up quite a bit.

We just got back on a round trip from west AZ to SoDak and back. The tires were on the trailer my dad had. The tires were 4 years old (spent all those years in SoDak), and surprisingly the tread was nearing the wear bar which is an experience that i've never had before. I was thinking they were "due"...but we made the trip without a hitch until 200 miles from my house when one let go..... third one I've blown out on various trailers and have yet to lose a fender.... lucky!! We ordered this trailer with 16" tires as I'd been lured into the trick of the day that 16's were the way to go. Jury still out on that one, but I do agree that there are a lot more choices.... including LT tires. I bought a set of "Hi-Run" ST tires. They are chinese (as were the OE set), but only have a max cold air rating of 80. Same load rating and ply that I can see, but the OE tires were rated 95psi on the sidewall.

I have a hard time buying an expensive tire here.... on my Haulmark trailer, which had 15" tires I did two sets of the OE Goodyear D Marathons (first set was recalled), Carlisle D rated, some no name D rated, Maxxis E rated, and then some no name cheapo E rated that were on it when I sold it.

The only other 16" option I've read up on is the 14 ply G rated tire. These have a cold psi rating of 110 and you have to have the wheels that will support this which my steel wheels are not. Not sure if there is a wheel in my 6 lug set up either... Most I found were 8 lug. Here's an example... http://www.ebay.com/itm/LT235-85R16-LRG-...4e1&vxp=mtr

Personally my next set of 16's are going to be LT truck tires.... keep hearing more and more people perfering this route.