What's up with snow type tires on new trailers?

JandL, those are some fine looking tires; indeed, the very definition of “knarly.”  But, that being said, I still have some uncertainties about such tires on a trailer and whether they are really advantageous.  

In your link, you point out a number of differences between the LT and ST tires, but it’s not so clear whether the difference present an advantage. The design needs for each type of vehicle are not necessarily the same.  If I understand your analysis, the advantages to the T/A tire are that it has a larger diameter [thus slightly taller], is a half inch wider, has a weighs more and has a higher speed rating.  

The width of a tire may or may not provide an advantage in that it is the amount of tire surface area actually in contact with the road that really matters.  On dry or rain wet pavement, a T/A tire may actually have less “rubber on the road” as a more conservative designed tread.  Certainly, when you’re in mud or snow, the surfaces area of the tire in contact with the surface on which you’re driving increases [with a declining coefficient of friction], but at speeds appropriate to those conditions, is it really a significant advantage?  And how many times do most Podders drive in those conditions?

The aspect ratio of 75 gives you a slightly higher tire, so you gain about a .4 inches in ground clearance [the other half of that height advantage is above the center point of your axle so it doesn’t count].  The slightly higher sidewall also increases stress on the sidewall, which is one of the strength factors that’s designed into an ST tire.  They have heavier fabric in the tire body so if you are comparing a 6 ply tire, the ST would be inherently stronger and better able to resist the lateral forces on the sidewall than a 6 ply LT.

The fact that the tire is heavier is of dubious advantage in that it adds to the GVW but the extra weight is likely the additional thickness of the rubber on the tread which adds no strength to the tire.  

The speed rating is nice, but driving trailers over 65 mph may not be such a good idea and in many states, for example CA, it’s illegal.  Speed rating on a tire is a function of the rubber compounding and it’s resistance to heat and potential tread separation.  And, there is, at least on e-Trailer, a pretty good selection of ST tires that have an M rating for speed [81 mph].   Check out this 10 ply E load rated tire for example:  https://www.etrailer.com/Tires-and-Wheels/Kenda/AM10303.html

The weight capacity difference between the ST and the LT on the two tires you compared presents a distinct disadvantage for the LT, to the tune of 1,160 pounds less capacity.  And if you go to the tire in the link on e-Trailer, its load capacity for two tires is 2,430 pounds greater than the LT.  Additionally, the extra steel they put into the ST tires allows them to run at much higher pressure, thus reducing the rolling resistance of the tire.

My interest in all terrain tires for our Pod is to avoid having to wallow around in the snow putting chains on when we cross the Sierra Nevada mountains.  It doesn’t look like that can be avoided by A/T tires.  I checked into the chain/snow tires rules for CA and NV and both states require chains on vehicles towing a trailer, both for the TV and at least one trailer axle that has brakes.  A quote from the Nevada rule:  

“All vehicles, including four wheel drive vehicles, that are

towing trailers must have chains on one drive axle.

• Trailers with brakes must have chains on the braking axle.”

Thus, it looks like, at least in those states, I’d still be wallowing around in the snow messing with chains.

So, aside from really cool looking tires, the advantage still seems to be with the really boring and ordinary looking ST tires.