ST vs LT Tires - Montana Owners Club

cgaskins · 11-12-2010, 02:39 AM

Ok, I have been following various replacement tire posts on this forum and RV.net forum.

I am struggling with going with Maxxis ST tires or BFGoodrich LT tires. The price is about the same for me here in Austin, Texas. What I have not seen on any of the forum posts is a definitive / technical list of the differences between ST and LT tires other than a deeper tread. I just see "Oh, LT tires are higher quality than ST tires". What I want to know is technically why this is true.

Thanks,
Chris

Tom S. · 11-12-2010, 03:35 AM

To make sure we are comparing apples to apples, I am assuming the weight rating on the two tires is equal or close to being equal. ST tires are constructed to allow more side wall flex. To understand why this is needed, look at you axles/wheels sometime when you backing up and making a sharp cut. However, the extra side wall flex may be the reason why ST tires come with a lower speed rating, normally around 65 mph.

The weight rating is the only thing stopping me from going from ST to LT. I wish "E" rated truck tires had the same load capacity as "E" trailer tires.

steves · 11-12-2010, 03:46 AM

Suggest you check out our resident tire expert (lonnieB) and see his recommendations.

BB_TX · 11-12-2010, 04:17 AM

Oddly enough in this day of instant information, it is difficult to find much on "facts" about using ST vs LT tires on a trailer. Google nets lots of hits. But most all are forum discussions such as this one with people expressing their opinions.
One site that does give some information is Discount Tire "trailer tire facts". But not really a should you/shouldn't you type argument. An interesting bit of info though is the statement that ST tires are not designed to wear out. Apparently they think the limited time frame (3-5 yrs) will run out before the tire wears out.
Take it for what it is worth.

ols1932 · 11-12-2010, 04:25 AM

One of the major problems you may find with ST tires is their availability. Not all tire dealers handle the vast amount of sizes. In an emergency, this could be a hindrance. LonnieB has posted at different times about the LT vs. ST tires.

Orv

cgaskins · 11-12-2010, 04:25 AM

I posted this same question on the RV.net forums and someone pointed me at the following post which is exactly what I was looking for...

http://www.rv.net/forum/index.cfm/fu...pging/1/page/1

Ozz · 11-12-2010, 07:52 AM

I am going through this now myself, now I am concerned about the wheels. I thought I was going to Michelin's, but maybe not...
Lonnie listed Michelin XPS Rib, Bridgestone Duravis R500 Commercial LT, then BF Goodrich Commercial TA, Bridgestone Duravis R250 Commercial LT and then Firestone Transforce H/T in that order for LT235/85R16 Load range E.
Mamma....

helmick · 11-12-2010, 08:34 AM

We have towed about 18,000 miles on our Michelin XPS Rib. We are not sorry we spent the extra money.

sreigle · 11-12-2010, 08:35 AM

We went to the BF Goodrich Commercial T/A in an LT size on our prior Montana and it was flawless for 9,000 miles. Then we traded for this Montana. This one also has LT tires but they're LT tires made for trailers (Goodyear G614).

Thanks for the link. Very informative and interesting.

One thing I noticed with our tires was the difference when just lifting and comparing an ST and LT tire in approximately the same sizes, same load range. It left no doubt in my mind which will be on our trailers from now on.

Someone told me the RVIA requires a fifthwheel to have ST tires in order to be RVIA certified. Does anyone know if that's correct? I know back around 2005 Keystone put LT tires on Montanas for a short period. So maybe the RVIA rules changed after that?

TLightning · 11-12-2010, 12:54 PM

IM very HO, any LT tire made any where but China is better than any ST tire made in China. If the ratings work, go for the LT...that's what many of us have done.

BirdingRVer · 11-12-2010, 01:16 PM

Quote:

quote:Originally posted by BB_TX

An interesting bit of info though is the statement that ST tires are not designed to wear out. Apparently they think the limited time frame (3-5 yrs) will run out before the tire wears out.
Take it for what it is worth.

They just know that the will blow out before they can wear out.

exav8tr · 11-12-2010, 02:15 PM

Charles Wade, Keystone District Rep, said, at the '08 Spring Rally in Tucson AZ, that the RVIA required the tires to be ST and that is why they were on ours. He admitted they were not the best tires in the world but he had to comply and, at the time, no American Companies were making ST tires due to low demand. I went with the Goodyear LT G 614 RST last year. The LT in this description refers to Load rating and NOT Light Truck. You must see the Goodyear website to understand this. The RST stands for Regroovable Specialty Tire which Goodyear only sells as a trailer tire. Expensive but well worth the peace of mind.....This tire is rated for 3750 lbs at 110 psi. You do not have to put that much air in them as I run 95 in mine according to the Goodyear tire and loading charts for the G614.

firetrucker · 11-12-2010, 03:00 PM

The Goodyear G614 listed on the Goodyear website is an LT235/85R16, which is the designation for a light truck tire that is tested according to the procedures and specs referenced earlier in the thread. Notice in the load/inflation table that all the RV tires that are on larger diameter rims with much higher load ratings have dropped the initials preceding the tire size, so they are probably tested to an entirely different set of specs (which might be interesting to research).

Bob

exav8tr · 11-12-2010, 04:23 PM

I would like to make it clear that, upon speaking to several Goodyear Reps, the G614 is not designed for trucks. I also read that on one of their sites but cannot locate it again. These tires carry the LT designation but you cannot find them when searching for truck tires, at least I can't. This is my disclaimer, you may do as you want but please think twice before putting them on a truck. Only time will tell if we made the right choice, but I do feel much better with them on compared to them Made in China things......I have addressed this issue in the past and will leave it here......

Tom S. · 11-13-2010, 01:24 AM

Quote:

quote:Originally posted by cgaskins

I posted this same question on the RV.net forums and someone pointed me at the following post which is exactly what I was looking for...

http://www.rv.net/forum/index.cfm/fu...pging/1/page/1

That is a very informative link but it misses one point: the load difference between ST and LT tires with the same rating. My "E" rated LT tires have a max load rating of 3080, while my "E" rated ST tires have a max load rating of 3450, so when they test each at maximum load, or a percentage of maximum load, the ST tires have a larger load than the LT tires.

I also agree with the statement by others that ST are most likely designed to expire by age rather than wear - for most people. People who travel a lot however do wear these tires out, as they are not designed for high mileage. Given the proper load rating, a good high mileage truck tire (Michelin comes to mind) would provide far longer service than a ST tire for someone who puts a lot of mileage on their trailer, but all tires (not just ST) have age limitations/recommendations. Which means installing a high mileage tire on a trailer that sees less than a 1,000 miles a year travel is a waste of money since the tire will go far past its intended life span before it wears out (just like what was said about ST tires.).

In summation, there is no single tire that is ideal for every person. Choices should be made on what the individuals needs and requirements are. One extremely important part of the "needs" is how much weight each one of your trailer axles carries loaded. This figure can only be known by having the trailer weighed one wheel at a time, and very few owners ever have this done.

SlickWillie · 11-13-2010, 01:45 AM

One thing is for sure for me; I'd rather run overloaded on USA LTs than run Chinese STs. Chris over on rv.net did some research, and posted the test requirements....that was all I needed.

I suppose the requirements have changed, but I know Keystone was using LT tires on fifth wheels in 2005.

Lee F. · 11-13-2010, 03:26 AM

When I bought my new Montana I refused to accept the Chinese tires that were on it. I asked for Michilin LTs and offered to pay the difference, but was told they could ONLY install ST tires. They gave me Maxxis ST Radial tires as an even exchange. Everything I have read indicates they are good tires, unlike the ones made in China.

sreigle · 11-14-2010, 10:04 AM

I might point out that although the G614 carries the LT designation, right on the Goodyear website for the G614 it says "DESIGNED SPECIFICALLY TO HANDLE THE DEMANDS OF TRAILER APPLICATIONS." That's in all caps because I copied/pasted it.

http://www.goodyear.com/rv/products/g614rst.html

SlickWillie · 11-14-2010, 10:31 AM

Quote:

quote:Originally posted by sreigle

I might point out that although the G614 carries the LT designation, right on the Goodyear website for the G614 it says "DESIGNED SPECIFICALLY TO HANDLE THE DEMANDS OF TRAILER APPLICATIONS." That's in all caps because I copied/pasted it.

http://www.goodyear.com/rv/products/g614rst.html

Also, I believe the RST is "radial special trailer".

TLightning · 11-14-2010, 11:15 AM

Quote:

quote:Originally posted by exav8tr

Charles Wade, Keystone District Rep, said, at the '08 Spring Rally in Tucson AZ, that the RVIA required the tires to be ST and that is why they were on ours. He admitted they were not the best tires in the world but he had to comply and, at the time, no American Companies were making ST tires due to low demand.

I too have heard this. However, I have personally seen LT tires on new RVs on dealer's lots. Don't know how they get around it, but I'd take the LTs long before the STs.

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