LT Tire vs ST Tire

Huntindog wrote:
Here is a link to a very good explanation of the govt. testing requirements for each tire type. The actual govt. regs are available, but are difficult and time consuming to research as they keep referring to different sections of the law.
This person did all the work and put this together:
Plain English Testing standards for ST and LT Tires

That so-called "study" gives neither sources nor references of any kind for the information it purports to base its conclusions on. Well, except for nods to other posters here in the Forums. It reads more like a church bulletin than a scientific paper: preaching articles of Faith to The Converted.

Best advice given here came early on: Consult a local tire guy you trust, and buy accordingly.

D and A plus 6 wrote:
Thanks for all the in put. I'll do some pricing. Thanks again.

Hard to help with suggestions without current size and load.

I've read a couple of threads about this question. It feels more like the sort of forum "debates" that are all over the web. The only facts I can glean from this discussion are:

1. ST tires are designed and built for trailers (not saying anything about quality, but just that ST's intended use is for a towed vehicle).

2. LT tires, by definition, are required to have very good traction and turning ability. In addition, the load ratings for LT tires vary as do the load capacity of the vehicle.

3. (not mentioned specifically)TT's are towed millions of miles a year with no startling frequency of tire failures. No evidence has been provided that any type of tire fails more or less often than another for this use.

People who have no problems with their tires are hardly motivated to post to forums expressing that. I, for one, expect my tires to perform. The number of people who post here is tiny compared to the RV population as a whole. On a typical weekend trip, I see more TT's on the road than the total number of people currently posting. We all do.

What's the point? Simply that we represent a tiny fraction of people towing stuff. All of the evidence posted is anecdotal; either personal experience or interpretation of standards not meant to be used as comparisons between different uses.

While cost is critical to trailer manufacturers, saleability trumps cost saving every time. Sure, there are "better" tires than the ones that came on our TT's. However, no reputable testing organization has objectively tested ST tires and issued a quality comparison (Consumer Reports where are you?). Definitely, there is no objective evidence that LT tires are better for towed vehicles. There is also no evidence they are worse.

It's all opinion.

Wishin wrote:
I think everyone can agree that if you can go to a tire that has a higher load rating, your chances of having an issue with a tire will go down. Personally I believe that LT tires are generally of higher quality compared to ST tires, but I can't prove it. My tires are so small that LT tires are not an option for me anyway. Another disadvantage of ST tires is the 65 mph speed limit. I don't normally drive faster than that, but occasionally run slightly over. LT tires are generally rated for 99 mph.

I'd try to find a tire (ST or LT) that has a higher load rating than what you have now if it will fit under your trailer with enough clearance and also fit your rim. New steel rims for a trailer really aren't that expensive anyway if you can go up a rim size or need wider rims to fit a bigger tire. Giving your self more load rating will give you a better margin of safety regardless of tire type. Many trailers come with tires with barely enough capacity which I think is part of the problem.

With all due respect, IMHO no one towing a trailer has any business going over 65 mph. So the speed rating on ST tires shouldn't be a factor. Again, IMHO.

I think everyone can agree that if you can go to a tire that has a higher load rating, your chances of having an issue with a tire will go down. Personally I believe that LT tires are generally of higher quality compared to ST tires, but I can't prove it. My tires are so small that LT tires are not an option for me anyway. Another disadvantage of ST tires is the 65 mph speed limit. I don't normally drive faster than that, but occasionally run slightly over. LT tires are generally rated for 99 mph.

I'd try to find a tire (ST or LT) that has a higher load rating than what you have now if it will fit under your trailer with enough clearance and also fit your rim. New steel rims for a trailer really aren't that expensive anyway if you can go up a rim size or need wider rims to fit a bigger tire. Giving your self more load rating will give you a better margin of safety regardless of tire type. Many trailers come with tires with barely enough capacity which I think is part of the problem.

All the above being said there are thousands of trailers running ST tires. Carlisle has a good reputation (the new RH tires) and Maxxis has a small vocal group that supports them here on this board, although Maxxis market share is miniscule compared to other manufacturers, due to a small distribution network for reasons only Maxxis knows.

Here is an interesting example of "your experience may vary". One poster in this thread stated that ST sidewalls are stiffer and therfore less prone to sway than LT tires. My experience was opposite that. The ST tires that came on my trailer were very flexible. I noticed when I took them off the wheels, I could easily with my fingers, flex the sidewalls. The LT tires I replaced them with ( Kumho 857 ) are noticbly stiffer by touch, and also make the trailer tow in a much more stable manner at highway speeds.

For what it't worth, the ST tires I took off were Freestar 205/75-14.
In fairness to the Freestars, none of them failed while I was running them. They are now in use on a couple of lightweight utility trailers that belong to friends, and they are working fine in that application.

Bottom line for me is, it's LT tiresall the way, on all of my trailers.

Bears Den wrote:
I only want to say is LT/ST who cares. What works for you may not work for the next guy. I had Goodyear Marathons on my old trailer, would'nt put them on a shopping cart but the next guy may have good luck with them. I have had ST tires on both my trailers and not a problem since replacing my Marathons. As they say, opinions are like, well you know, everyone has one. Do some research, find what works for you and stick with it.

+1

I currently have Goodyear Marathons on my trailer and they are 10 years old. I am replacing in the beginning of next season for two reasons...

First) They are 10 years old! I have had the trailer for 2 seasons and didn't know that tires should be replaced more often. Mine look like new, so I just thought they would be okay. Since so many campers around me are always dealing with blow-outs, I decided to not push my luck with the old tires.

Second) All-in my trailer weighs 6006 lbs ready to camp. The tires I have now appear to be rated for 1400 lbs each, multiply by four and you get 5600 lbs maximum. I understand that some weight is transferred to the truck, but that is just too close for comfort.

Thanks for all the in put. I'll do some pricing. Thanks again.