comparison ST vs LT Goodyear

Old-Biscuit wrote:


My 2 axle 5th wheel came with LT tires (all four positions and spare)OEM Goodyears and they are warranted for use on my 5th wheel

I don't think NuWa would put them on there without a warranty agreement with GY.

Your Rig

FastEagle

Gdetrailer wrote:


So.. are YOU a tire ENGINEER?

I you take a real close look at ST tire treads you will find less than 1/4 the tread on it compared to a LT tire. This in it's self can account for a considerable amount of weight difference.

Third, ST tires are NOT designed for TRACTION, infact the rubber compounds ARE designed to LOSE traction . This is extremely important when using on two or more axle trailers. The tires on a multiaxle trailer MUST be able to "hop" when making turns. Otherwise you will heavily stress your axles, bearings, springs, hangers and yes the frame of the trailer. Your axles can shift side to side up to two inches while making turns.

This leads to the FOURTH POINT, ST tires DO have extra strength designed into the sidewalls, they have to in order to withstand the side to side stresses of multiaxles.

While there are folks putting LTs on trailers it doesn't mean that it really is the right or correct thing to do in fact some tire manufacturers DO NOT RECOMMEND LT tire usage on trailers. Doing so you might find yourself without any warranty or recourse..

Not a tire engineer but I stayed at a Motel 6 once.......

My 2 axle 5th wheel came with LT tires (all four positions and spare)OEM Goodyears and they are warranted for use on my 5th wheel

Gdetrailer wrote:

PartyMarty wrote:
why are ST tires overrated ?
From the tirerack website .


So the Goodyear ST tire is rated for 112.4 % higher load rating than the equivalent Goodyear LT tire .
And they will sell this ST tire for only 86 % of the LT tire .
And the ST tire has less mass for cordage , plys , caps and so forth because it weighs 76 % of the Goodyear LT tire .

This is very telling as to how much lower the ST standards are in relation to the LT standards .

Further the ST tire has plainly stamped on the sidewall " for trailer use only " .
The LT tire has no disclaimer .

So.. are YOU a tire ENGINEER?

I doubt it.

On the surface your "conclusions" would appear to be "spot on", BUT, there not even close.

First of all you have TWO DIFFERENT sizes of tires due to the SERIES (IE WIDTH).

Second of all the two tire "types" are designed for SEPARATE uses.

I you take a real close look at ST tire treads you will find less than 1/4 the tread on it compared to a LT tire. This in it's self can account for a considerable amount of weight difference.

Third, ST tires are NOT designed for TRACTION, infact the rubber compounds ARE designed to LOSE traction . This is extremely important when using on two or more axle trailers. The tires on a multiaxle trailer MUST be able to "hop" when making turns. Otherwise you will heavily stress your axles, bearings, springs, hangers and yes the frame of the trailer. Your axles can shift side to side up to two inches while making turns.

This leads to the FOURTH POINT, ST tires DO have extra strength designed into the sidewalls, they have to in order to withstand the side to side stresses of multiaxles.

While there are folks putting LTs on trailers it doesn't mean that it really is the right or correct thing to do in fact some tire manufacturers DO NOT RECOMMEND LT tire usage on trailers. Doing so you might find yourself without any warranty or recourse..

I guess I live a charmed life, 20yrs RVing using those horrible cheapo lightweight ST tires :B Not to mention have tempted "fate" not once but twice on two different TTs with those well hated junky Carlisles that everyone here on this forum LOVE to bash but yet I never had had a problem with them.

Get a grip, underinflation, overloading and road debris are your main culprit in why tires blow out... What are YOU guilty of?

Yikes. The above post has some, uh...."interesting" comments.

I don't know about the rest of you guys, but I kind of like my trailer tires "to have traction".

From the "for what it's worth department", one of the trailers I own is a Load Trail equipment trailer. In the manual that came with it, it states that either ST or LT tires are recommended for use on it.

aaaaaand were off......

PartyMarty wrote:
why are ST tires overrated ?
From the tirerack website .


So the Goodyear ST tire is rated for 112.4 % higher load rating than the equivalent Goodyear LT tire .
And they will sell this ST tire for only 86 % of the LT tire .
And the ST tire has less mass for cordage , plys , caps and so forth because it weighs 76 % of the Goodyear LT tire .

This is very telling as to how much lower the ST standards are in relation to the LT standards .

Further the ST tire has plainly stamped on the sidewall " for trailer use only " .
The LT tire has no disclaimer .

So.. are YOU a tire ENGINEER?

I doubt it.

On the surface your "conclusions" would appear to be "spot on", BUT, there not even close.

First of all you have TWO DIFFERENT sizes of tires due to the SERIES (IE WIDTH).

Second of all the two tire "types" are designed for SEPARATE uses.

I you take a real close look at ST tire treads you will find less than 1/4 the tread on it compared to a LT tire. This in it's self can account for a considerable amount of weight difference.

Third, ST tires are NOT designed for TRACTION, infact the rubber compounds ARE designed to LOSE traction . This is extremely important when using on two or more axle trailers. The tires on a multiaxle trailer MUST be able to "hop" when making turns. Otherwise you will heavily stress your axles, bearings, springs, hangers and yes the frame of the trailer. Your axles can shift side to side up to two inches while making turns.

This leads to the FOURTH POINT, ST tires DO have extra strength designed into the sidewalls, they have to in order to withstand the side to side stresses of multiaxles.

While there are folks putting LTs on trailers it doesn't mean that it really is the right or correct thing to do in fact some tire manufacturers DO NOT RECOMMEND LT tire usage on trailers. Doing so you might find yourself without any warranty or recourse..

I guess I live a charmed life, 20yrs RVing using those horrible cheapo lightweight ST tires :B Not to mention have tempted "fate" not once but twice on two different TTs with those well hated junky Carlisles that everyone here on this forum LOVE to bash but yet I never had had a problem with them.

Get a grip, underinflation, overloading and road debris are your main culprit in why tires blow out... What are YOU guilty of?

So steering only tires are a poor quality because they are made for the steering position only… good grief, charley Brown…

I guess the purpose of the thread is to try to prove that weight is the difference, and the proof of a tires quality…

It’s like saying I have a 5 lb. bag of apples that only weighs 4.44 pounds on the scale and I have a 5 lb. bag of oranges that weighs 4.92 pounds…
It’s obvious the oranges are better for you than the apples are…

Tire weight is part bulk, part material selection and/or the build processes used… there are way too many variables that we aren’t even privileged to, to equate weight alone as evidence of quality…

Recipes of chemical or rubber compounding are one of the most closely guarded secrets of the tire industry… these compounding can be developed to be lighter or heavier to achieve a higher quality for a given purpose…

Cap ply’s might be made from single yarn or twisted cords… the single yarns can be cheaper, lighter, and thinner , but they can also be higher quality, improve heat dissipation, and reduce belt edge separation… the beading can be built differently in one tire from another… the amount of and the quality of the inner innerlinner material, more things than we could ever know…

Weight alone is evidence of nothing without explanation of the difference…

Even tires from the same mfg. might have different LT or ST model tires of different weights even in the same size and LR and it doesn’t equate to Quality…
For example from the 2012 Carlisle catalog to keep it apples to apples, that list the radial trail RH 205x75x14 LR C with a load rating of 1760 listed at 25.9 pounds…

Yet from the same catologe Carlisle 215x75x14 LR C with a load rating of 1870 listed at 25.8 pounds… the tire with the higher load capacity has a lower weight…

The 225x75x15 LR C is bigger and weighs more than the 205x75x15 LR D but both have the same rated carrying capacity… citing and using weight alone for different tires is misleading at best…

We outsiders don’t have enough information to know or say what the weight alone means…

Of the two tires mentioned the LT has a wider section width, tread width, and a 1 inch larger diameter…
All we know is they are two different tires…

I think a better comparison would have been the ST235/85R16E which is basically the same size as the LT. That ST has a load capacity of 3640# at 80 psi. But, GY doesn’t build that sized ST tire.

What a speed rating basically tells us is the tire can carry its full load capacity at its maximum speed restriction. Beyond that it will start heating beyond what is normally dissipated by thermal equilibrium. It is then being damaged by excessive heat. The hotter it gets the more severe the damage. Each time it’s damaged it gets closer to its failure point.

FastEagle

Interesting comparison. At first blush it appears the ST tire is a better option for trailers. However, as with many things, numbers do not tell the whole story. But I have some popcorn handy so let the battle begin!

Load carrying capacity decreases as speed increases- that's a main reason that LT tires are rated to carry less weight than STs of a similar size. Standards dictate that ST's are limited to 65 mph, and LT's speed ratings begin at 75 and go up from there.

Differing inflation pressures also play a role. Good explanation of this phenom at this Bridgestone link.

But I'm sure that sounds way, w-a-a-a-y too simple, so stay tuned! :B

P.S.:

Can you link to the tire you're looking at? Can't find a Goodyear LT235/85"R"16 at Tire Rack.