LT Tires vs. trailer tires

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jimnade

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Feb 22, 2006
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La Grange, California
I am inching ever so close to replacing my ST tires with LT tires. I have -225 75R 15- tires on my Alpenlite 5th wheel and have gone through the gammit of trailer tires. Are many RVers changing to the truck tires? Is there a reason why the trailer tires have such soft side walls; 2 ply? If I change to LT's will the ride be bumpier,  bouncing more and jiggling the world out of the trailer?

Also, I was just informed that Carlisle (and maybe others) are manufacturing Load Range E trailer tires for my 15 inch wheels...a couple years ago I was told they did not exist. At any rate, they do now. Would I still be better off using a truck tire?

I would be most grateful for any input...and, if this is already a thread would someone please reference it for me. I thank you all.

Jim
 

Gary RV_Wizard

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There is no standard for the ST designation except that they are designed for exclusive trailer use and cannot be used on a passenger vehicle or truck of any kind. That permits the tire manufacturer to take some liberties with the design that would not be possible if the tire had to be safe for use on the steering wheels of a vehicle.  In general, ST tires will have stiffer sidewalls than other types, use different rubber compounds and have different tread designs. These may or may not make them "better" for trailer use.

LT tires are designed for light trucks (and now, SUVs) and also generally have stiffer sidewalls and sturdier construction than P (passenger car) tires. However, the retain the characteristics needed for safe steering and can be used on any vehicle, in any tire position. LT tires are available in load ranges suitable for heavier railers and make an excellent "trailer tire".  I doubt if you will notice any difference in ride versus an ST tire. You will probably notice a difference in price, though - usually much less! There's plenty of competition in the LT market and very little in the ST market.
 

jimnade

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Feb 22, 2006
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La Grange, California
Gary -
Thanks for the input. A few months ago you, and several members, helped me troubleshoot my furnace...again, thank you. Now the tires are at the top of my list.

I have 6 lugs on my drums and plenty of clearance to accomodate a larger tire. If I purchased 16" rims along with an appropriate LT tire (for example a ribbed 235/85R/16) would our trailer be happy with its' new booties? I know our rig is, and always has been, right at the teetering edge of "too much weight for the 225/75R/15." I know the manufacturers save a few bucks.

We have been most fortunate with our flat tire experiences. I have heard horror stories of blow outs that ripped fellow RV'ers rigs to pieces. So...I need to feel confident about my tires. I have always done a walk around prior to taking off from every stop...now, I get nervous as I approach the other side. I just keep praying that I will see a fully inflated round rubber tire.

I thank you in advance for any reply.

Jim
 

zippinbye

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Las Vegas, NV and Pender Island BC
Gary RV Roamer said:
There is no standard for the ST designation except that they are designed for exclusive trailer use and cannot be used on a passenger vehicle or truck of any kind. That permits the tire manufacturer to take some liberties with the design that would not be possible if the tire had to be safe for use on the steering wheels of a vehicle.  In general, ST tires will have stiffer sidewalls than other types, use different rubber compounds and have different tread designs. These may or may not make them "better" for trailer use.

LT tires are designed for light trucks (and now, SUVs) and also generally have stiffer sidewalls and sturdier construction than P (passenger car) tires. However, the retain the characteristics needed for safe steering and can be used on any vehicle, in any tire position. LT tires are available in load ranges suitable for heavier railers and make an excellent "trailer tire".  I doubt if you will notice any difference in ride versus an ST tire. You will probably notice a difference in price, though - usually much less! There's plenty of competition in the LT market and very little in the ST market.

Gary,  I too am leaving the ticking tim bomb world of ST tires, wanting to move up to 16" from my  St225/75 x 15s.  I have 4.25" of space between existing tires on their respective axles.  I randomly compared dimensions between what I have and another trailer tire, ST235/80 x16 (just for comparison of sizes, no way ST tires get one more dollar from me).  Using radius or both diameters divided by two, my space between tires would diminish by a theoretical 2.6", leaving 1.65" of clearance.  I'm not sure how much independent movement my two axles could have, especially in a tight maneuvering turn, not to mention circumference expansion with speed.  Any thoughts on a minimum margin between tandem axle tires?  Also, I'd appreciate knowing about specific brand/model LT tires you feel would be a good choice.  Thanks!
 

markandkim

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Swansea MA.
Even though this topic has been beat to death, I still learn more about the difference between ST and LT tires. When it comes time to change mine, I'm going LT. I now believe they won't explode like ST tires will.

I'm listening.
 

kdbgoat

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zippinbye- one other thing to consider when going to larger tires is the clearance at the top of the tire.
 

scottydl

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When shopping for LT tires (for a trailer), make sure they have the same or higher weight ratings of your current ST tires.  I found LT tires to be cost prohibitive when looking at models that fit on my current 15" rims, and were heavy duty enough for my 32' double slide TT.  I did "upgrade" to E-range ST radials, over the factory D-range ST bias plys that were replaced... so I feel better about that.
 

lone_star_dsl

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For me, LT tires are the only way to go.  I've ran them on various trailers for years both in recreational and commercial use.  My toy hauler came with a set of year old trailer tires and I ran them for the first year I owned it.  I switched to LT tires this spring and the difference was palpable.  Less sidewall flex means that the trailer tracks better than before, and the higher speed rating and reserve capacity help my nerves when on the road.
 

Gary RV_Wizard

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The trade-off is that LT has a higher speed rating but lower weight carrying capacity for any given size. Typically you need to use a larger size LT to get the same capacity as an ST.

There are some pretty crappy ST tire brands out there too. Cheap, but quality control is lacking and failures all too likely.
 

martin2340

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Sanatoga, PA
I too am looking to replace 4 tires on my TT after having a total destruction blowout on my last trip. I was doing some research and looks like the Carlisle ST load range E has a weight rating in that size of 2585 lbs and is a 10 ply tire and reasonably priced under $70.00 online. Of course shipping and mounting are going to run you just as much. I will try and find a local dealer to purchase from.
 

HueyPilotVN

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I carry lots of weight in my trailer.  I upgraded to Goodyear G rated tires with a rating of about 4,000 pounds per tire.  One word of caution is that some tires like these require 110 psi to support the max load and your wheels may be only rated for about 80 psi.  I had to replace all 10 wheels to support this pressure
 

scottydl

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^^ And don't forget that your trailer axles have weight carrying limits too.  Upgrading tires to carry massive weight won't help (or could give you false security in your load capabilities) if your axles or brakes aren't rated to manage that same amount of weight.
 

Rene T

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HueyPilotVN said:
One word of caution is that some tires like these require 110 psi to support the max load and your wheels may be only rated for about 80 psi.

Bill, how do you find out hat pressure your wheels are rated for?  Is it stamped on the wheels someplace?
 

driftless shifter

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scottydl said:
^^ And don't forget that your trailer axles have weight carrying limits too.  Upgrading tires to carry massive weight won't help (or could give you false security in your load capabilities) if your axles or brakes aren't rated to manage that same amount of weight.

This is so true. Just last week I saw a single axle landscapers trailer on the Rayburn Tollway near Dallas Tx. It was loaded with about an 18" level load of masonry rubble. Drivers side of trailer axle had folded right over and the wheel was canted over far enough that that side of the trailer was on the ground, it ran the work truck right off the pavement into the median. I'm guessing it happened going over the whoop-dee-doo in the pavement I went over just before I saw the wreck. No injuries, work truck undamaged, Workers staring at it scratching their heads. I run this route every afternoon and had seen what was probably the same truck doing the same thing a couple times during the week, The driver was always driving it like he knew it was heavy, in the right lane going 60'ish in 70-75 MPH traffic. Lucky he didn't take anyone else out as he veered across the two lanes of traffic as he careened toward the median.

Bill
 

HueyPilotVN

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Rainy,

I have a friend at the corporate office of Discount Tire/Americas Tire and he called me after I got the new Goodyear tires and told me that the chrome wheels on the Stacker were not rated for 110 psi.  He actually gave me a great deal on the "Black Rock" brand aluminum wheels.  His attitude was that they made a mistake installing them on the wheels that were only rated for 80 psi.  I do think that they are stamped with the max pressure allowed but I cannot verify this for sure.

 

Rene T

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HueyPilotVN said:
Rainy,

I have a friend at the corporate office of Discount Tire/Americas Tire and he called me after I got the new Goodyear tires and told me that the chrome wheels on the Stacker were not rated for 110 psi.  He actually gave me a great deal on the "Black Rock" brand aluminum wheels.  His attitude was that they made a mistake installing them on the wheels that were only rated for 80 psi.  I do think that they are stamped with the max pressure allowed but I cannot verify this for sure.

Thanks Mr. camera!!!  :eek:
 

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