ST and LT tires ARE DIFFERRENT. The manufaturers will tell you so. ST are, in theory, designed for trailers that experience serious, belt breaking jackknifing. LT tires are designed to be on a truck, SUV, with thinner side walls for a better ride. GoodYear had an LT all steel tire that were put on heavy 5vers. These has a history of coming apart, sometimes with serious danage. Thus, they came out with the rST, for heavy 5ers. Completely diffrrent design.
So, just remember, when your LT tire comes apart on a heavy 5er(Or not so heavy?), you heard it hear first, not from the old wife.
Goodyear had a line of ST tires that are OEM on a number of reputable makers.
They will stand behind their tires if things go wrong. They are after he RV business and treat their customers well, especially if you go to corporate.

 

The G-rated Goodyear Unisteel G614 RST is DOT-labeled LT235/85R-16. I know. I have them on my 5th wheel. I've looked for myself.

Rusty

 

http://www.goodyear.com/rv/pdf/rv_inflation.pdf

All of Goodyears ST only have a 65 MPH speed reading.

And they only go to 65 lbs of air and 3000 weight, that is why you see LT going on the larger 5th wheels. The Michelin XPS Rib is still the best trailer tire up to its rating. Then you have to jump the GY G rated LTs.

SNOKING

 

ST (trailer tires) don't hold up at all. They don't support enough weight. They're just ok for light travel trailers and 5er's. But let's get serious here-LT's are needed instead. My horse trailers have triple 7000# axles with E rated tires on them.

The MTR's were advertised as a replacement for the Workhorse series, as being better built to handle rough roads. We put them on the trailer instead of the truck, just to see if they would last - they didn't. The only reason, I'd go with the XPS is because they can be re-capped.