I am starting this thread so that we can all learn from it - I want to know too!

I forgot to ask while at work.

Are they specially designed?
Are they stronger tires?
Or are truck tires better bets for rough going?
There are "E" and "F" rated trailer tires. What does THAT mean?
Why does it say "trailer only". Trailer tires are turned, twisted, skidded, and so on, much more harshly than ordinary tires - it does not follow (or so logic tells me) that an inferior tire is used on trailers. Are they built differently to compensate for that?
If it is unsafe to use a "Trailer Tire" on my vehicle, why is that?

Bottom line: Are trailer tires more or less safe than ordinary ones...

I know that rims are also marked (stamped into them) TRAILER USE ONLY. Why????

These and other questions I would like to seriously explore in this thread.


~Wolf

 

no input, just want to follow.

 

Here's a good place to start, from Champion Trailers: http://www.championtrailers.com/tire_art.html

Steve

 

HEY! I appreciate ya! I think I need even more in-depth info from my boss though - because he has been dealing with trailer tires for a lot of years.

Thing is - a tire company can say what they want - but actual road tests by owners can tell another story. I know a boy who has used trailer tires on a truck. But he's not what you call an expert...

JIM FERGUSON IS. I need to sit down and talk to him about what he thinks from all of his decades of experience....

But I know also we have a lot of members who have first hand experience. That would be good too...

 

I remember reading somewhere that radial ST tires are good for single axle trailers, but for tandem/triple axle trailers the preferred tire is still bias-ply ST's; supposedly the stiffer sidewalls help to shed heat (like when you're making a run from LA to Lake Mead with your 38' Eliminator in the middle of July).

Steve

 

Here is my understanding.

Trailer tires (ST) and truck tires (LT) both have stiffer sidewalls than passenger car tires. This helps eliminate trailer sway.

ST tires have UV inhibitors to keep them from breaking down in prolonged exposure to sunlight, as trailer tires tend to go south from rot quicker than you can wear them out.

ST tires are only speed rated to 65 mph, whereas LT tires are rated for higher speeds.

Most of the really heavy travel trailers and fifth wheels (10K lbs +), now come from the factory with LT tires.

I have heard that the testing and QC requirements for LT tires are much more stringent, as they're made for passenger vehicles.

I have had much better luck with the LT's than ST's on heavy trailers.

 

On class 8 trucks and trailers the difference in drive or steer tires and trailer tires is what kind of forces they are designed to withstand. A trailer tire is made to takes the lateral scrub from the axles on turns-especially on spread axle trailers- steer tires are designed to stand the force of 80,000 lbs. pushing on it on corners at 65mph. Steer axle tires can be used on the trailer but trailer tires cannot be used on the steer axle with out a chance of failing.
I don't know if the same applies to pickups and rv trailers but I think there is similar engineering in their design. Hope this helps.

 

one thing that ive heard, is if you use a regular truck/car tire on a trailler, is that you can bust belts in them from sharp backing turns when your loaded.

 

Pass. tires and steer tires are designed for braking and wet traction, while driving and while braking, trailer tires are not. The treads on steer tires (talking class 8 now) are designed to avoid squirm in the tread block itself while steering and braking. Thius is a default on all pass. and LT tires.

> There are "E" and "F" rated trailer tires. What does THAT mean?

In relationship to trailer tires

E = 10 ply
F = 12 ply

 

My travel trailer is an 04 and wieghs in at 10,000lbs loaded. I just noticed that the factory tires were showing signs of dry rot. I take very good care of my stuff and have treated these tires with the same respect as my truck tires. As far as cleaning and dressing the tires. Would I be better to replace these tires with truck tires?????? I want something that will last and give me good performance. This is only the third season for these tires. I would think you should get more than three years.

 

One hopes the factory tires were not Nankang...

Two things that might help are to cover the tires when the trailer is not moving, and if it is to be parked for a long time - support the axles with blocks to take the weight off the tires. That's a lot of tire covers, I know. But covers are cheaper than tires...

 

Don't know if Trailer Life Magazine has an electronic archive of articles, but they had a good article back around 2002-3? about trailer tires why and how etc.

From my vague recollection they have stiffer sidewalls since you don't want the trailer to sway side to side. They also have higher load ratings, which is shown by the E and F and of course the sidewall will spell it out. F is higher, but without looking it up I don't know how much.

One surprise I found was that at least my spare is a lower rated tire and if my trailer was at max weight, that tire would be over rating. Looks the same etc, but the rating is one notch lower than the other 4. So I guess the spare is not to be rotated into use and should be driven cautiously at lower speeds if your trailer is heavy.

If you have ever turned a trailer in a tight spot and parked, you may notice that the tires are twisted a LOT(almost cockeyed) and stay that way until you move the trailer. I suspect this is one thing they are designed to do that a passenger tire doesn't see much. This always worried me since I didn't think it was normal, but after years of reading TLmag I don't worry about it anymore.

These are just my recollections, and I am nowhere near expert.

Jim Henderson

 

Trailer tires (st) are designed to withstand the side loading that jim henderson brought up. Tandem axle trailers twist the axles severly when backing or turning hard, which transfers to the tires. I wouldn't use LT tires on a heavy trailer, they just aren't designed for these side loads. Trailer tires aren't just a gimmick to sell more tires, they are designed and built for a purpose, and that's it. In most cases thay don't cost as much as LT tires, so why not use the right tire? Also, if I would look at a used trailer to buy, and it had P or LT tires, i'm knocking your asking price right off the top for new, correct, tires.

-Scott

 

Funny, my bosses name is Fergusson...

 

> I would look at a used trailer to buy, and it had P or LT tires,
> i'm knocking your asking price right off the top for new, correct, tires.

I am not saying it is correct, BUT, I know several people, including someone on this board that bought my 1971 F-100 4x4, that use Ranger rims and P235/75r15 tires on their tandem car carriers.

So ... I think you have to draw a line between weight limits and type of trailers too. I think a fifth wheel or a travel trailer that tops the scales at 12,000+ empty deserves a different tire then a tandem axle landscape trailer. Same as a tandem dump trailer requires a different type tire too.

> I wouldn't use LT tires on a heavy trailer

I would, just depends on the trailer. If the trailer costs more then the truck or a small house, I would be more likely to use a very high quality trailer tire from a well known brand name. Though if I wanted a tire for off road use and clearance, my only choice would be a LT Load D/E/F tire.

I look at my tire purchases from the point of view of "is my choice going to kill someone else or myself".