I think this forum is dangerous

Passin Thru wrote:
Well, since running Michelin LTs on TTs, stock trailers and flat trailers to haul cars and tractors I probably know what I'm doing. I have never had 1 blowout with a Michelin. China Bombs are just that. My TT is an Arctic Fox 31 W, weighs right at 10500 and witth the Michelins pulls smooth and if you run onto the edge will follow you back onto the pavement. Of course most of you are perfect drivers, don't text and drive and never run off the edge and never have flats.

I also use trailers 4 to 5 days a week . Equipment 7K to 10K loaded . Equipment isnt cheap , bobcats run 50K a good landscape tractor close to the same . Safety is a big priority , wrecks , blowouts , all cost time and money , changing tires on an interstate isnt fun. ( at least with the bobcat you can take it off the trailer and lift the trailer up). I cant risk running ST tires with expensive equipment sitting on the trailer , been there and done that . Now with the RV ,its filled with my family . There is no choice for me but a LT tire . Sure I still could have a tire problem BUT with a LT I doubt it would be a failure of the tire , but more likely a road hazard .

Well, since running Michelin LTs on TTs, stock trailers and flat trailers to haul cars and tractors I probably know what I'm doing. I have never had 1 blowout with a Michelin. China Bombs are just that. My TT is an Arctic Fox 31 W, weighs right at 10500 and witth the Michelins pulls smooth and if you run onto the edge will follow you back onto the pavement. Of course most of you are perfect drivers, don't text and drive and never run off the edge and never have flats.

I had zero problems with these on a 1995 year model trailer:

"Marathon steel-belted radial trailer tires are the first radial tires designed specifically for trailering. With their two steel belts and heavy-duty, weather-resistant sidewalls, Marathon trailer tires provide longer wear, offer better traction, and greatly reduce your chances of experiencing tire failure."

Why would people think a quality ST tire is cheaper than an LT?

Likewise who said there are no cheap LTs.

Heck the OEM Wranglers on my TV are over $200.00 a piece and they are only "P" rated.

A person can go with what the industry recommends or do their own thing. The only one they have to please is themselves.

4X4Dodger wrote:

Slowmover wrote:
ST tires are the problem, not country of origin. Theyre fine for something other than a travel trailer. Speed rating is too low (like running a motor at redline) and against law to use on passenger vehicle. Quality is not inherent. As has been speculated, their recent invention means longer productive life on worn tire making machinery.

Spend a little more and upgrade to LT.

I am sorry but this idea you put forth shows a complete lack of knowledge of the FACTS. Keep in mind as you read it Every tire Mfg will say the same. This idea that ST Tires are somehow a "lesser" type of tire is just Flat-Earth-ism.

You can find the entire paper at: ST vs LT Tires

From: Carlisle Transportation Co. (I have posted this previously)

Use the Right Tire

Trailer tire requirements differ greatly from automotive or light truck
tires. Trailer tires are designated “ST” for Special Trailer tires.
Automotive tires are designated “P” for Passenger or “LT” for Light
Truck and are not designed for trailer use. Passenger or truck tires,
with their more flexible sidewalls, can result in trailer sway problems.
The stiffer, heavy duty sidewalls of ST tires are designed to control
and reduce sway problems. Trailer sway is dangerous at higher
speeds, with top heavy loads or on vehicles with inadequate
tongue weight.
– Trailer tires are designed for use on trailer axle positions only.
– Do not use P Passenger or LT Light Truck automotive tires
on trailers.
– Do not use ST trailer tires on passenger cars or light trucks.
– An "LT" designation, when shown on a trailer tire size specifies load
range only, it is not designed for use on light trucks.

The ST Difference

The construction, design, materials and testing used in ST Special
Trailer tires meet the higher load requirements, duty cycles and
special demands of trailering.
– Polyester cords in an ST tire are bigger than in a comparable P or
LT tire.
– Steel cords used in ST tires have a larger diameter and greater
tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and
ozone cracking, particularly conditions resulting from extended
storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and
rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower
section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than passenger tires.

You've refuted nothing. And if you want cheaply made and unsuitable for any passenger vehicle PLUS real problems with load and heat, you are welcome to them. Not so many years ago there was no such thing as ST. LT was all we had. And they are a better choice for a travel trailer. Good luck

http://www.rvtripwizard.com/rv-info/state-road-laws.html The following states allow passangers To ride in either a fifth wheel or a bumper hitch trailer . In Arizona , California ,Iowa , Indiana , Kansas , Maryland , Minnesota , Missouri , Montana , Nebraska , New Jersey , Oregon , Pennsylvania , South Dakota , Wisconsin , and West Virginia .

Is it the smartest thing to do ? I would say no . But it is legal and I am sure it is done . Now legally you can not run ST tires on your trailer with the passengers inside . So what do you run ? Now in these states it could be argued that all travel trailers in those states would be considered passenger vehicles and they never should have even had ST tires on them in the first place. The trailers should be equipped with a tire rated for the weight capacity and safe enough for people . Now the ST tire doesnt accomplish this , But the LT tire does .

It is good to see a review the design facts about ST tires; unfortunately people confuse the more rigorous testing requirements of LT tires with their suitability for a load that they were not designed for.

Wrong assumption.
The FMVSS test specs speak for them selves and show us in certain areas the LT out preforms the ST and is equal in strength and bead unseating tests.

I am sure an Indy racing tire undergoes a number of extreme performance tests also but that does not mean it is good for trailer applications either. Either you trust the tire folks and their design research or you do not.

Racing type tires do not come under the same FMVSS tests as our P/ST or LT tires. Agree they won't be the best idea for a trailer position.
I trust the ST tire manufacturers has done their research and design just as I trust LT tire manufacturers have done their research and design for a LT tire can be used in a steer/drive or trailer position. Same for a P tire which also is used as a multi purpose tire.

westend wrote:
For those looking for ST trailer tires it may be noted that the Carlisle ST Radial Trail RH is speed rated at a higher MPH than other ST tires (87 MPH in common 14" & 15" sizes). Carlisle warns that it shouldn't be used at those speeds but is tested at the higher speed.

FWIW, I have them on my trailer and have had no problems for a couple of years.

Good to hear. My dealer doesn't carry these yet. They just replaced 4 Towmax STR's at 3,800 miles because 3 were starting to come apart.

It is good to see a review the design facts about ST tires; unfortunately people confuse the more rigorous testing requirements of LT tires with their suitability for a load that they were not designed for.

I am sure an Indy racing tire undergoes a number of extreme performance tests also but that does not mean it is good for trailer applications either. Either you trust the tire folks and their design research or you do not.


In case you were wondering Columbus started with four ships. However the forth ship was lost when it sailed off the edge of the earth!! I read it on the internet, so it must be true.

Slowmover wrote:
ST tires are the problem, not country of origin. Theyre fine for something other than a travel trailer. Speed rating is too low (like running a motor at redline) and against law to use on passenger vehicle. Quality is not inherent. As has been speculated, their recent invention means longer productive life on worn tire making machinery.

Spend a little more and upgrade to LT.

Good point on country of origin and speed ratings.
We had the same issues with ST tire when they were all made in the USA by our major tire makers.... many years before china tires started showing up at tire dealers or on our trailers.

This from the 5th wheel forum dated 9-22-09 by SeniorGNC that puts some real facts out here instead of PR hype from a tire chain store or a ST tire maker. Tire clicky link

Highlights were; Testing per the FMVSS in several categories shows ;

The testing for each tire is comprised of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.

1. The testing for bead unseating resistance is identical for a ST and LT tire.

2.The testing for strength is identical for a ST and LT tire.

3.The difference in endurance testing between a ST and LT tire is significant. Both tires are tested through a equivalent loading/time profile. However, the LT tire is tested at this profile at a higher speed (75 vs. 50 mph) and must still endure an additional 2 hour low pressure test without failure. Thus the overall test for the LT is far more rigorous than the ST test.

4.The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.

SeniorGNC did a good job of researching the many websites and all the FMVSS testing specs involved between the ST and LT.