ST vs LT tires

[IHnutz]

I am sure this has been brought up here before , but I couldn't find it. My CornPro brand GN flatbed trailer, GVWR =14,000#, came from the factory with LT265/85 R16 load range E tires. That is is size listed on the placard along with the recommended tire pressures of 85#.


I went to buy a new tire and was told "You can't put a "LT" tire on a trailer, it has to be "ST"tire." I asked "Why not?" He answered "Because "LT" means "light truck" and "ST" means "special trailer" and you are putting it on a trailer". I responded "But that is what the trailer manufacturer calls for!" He said " I don't care, you can"t put a truck tire on a trailer."


My question is, Why can't I put a an LT265/85 R16 load range E tire on my GN trailer when that is what the manufacturer calls for?

[chuckster57]

Because you went to the wrong tire shop.

[IHnutz]

LOL )



I agree, I really figured he was going to say "Because the ST tire costs more and I will make more money!" But seriously, what is the difference between an ST tire and an LT tire?

[chuckster57]

I’ll wait for the tire guru to answer but I believe the LT tires have a stiffer sidewall among other things. Lots of shops out here will put them on trailers.

[Ranchhand]

There will be a tire guru that says you shouldn’t but LT tires is what I use on my camper, 24 foot gooseneck livestock trailer and my 25 foot gooseneck flatbed. I have had zero issues using a LT tire on a trailer.

[tech740]

If the placard on the trailer calls for LT tires than that is all they should put on it. ST should not be mounted on that trailer by a tire shop. Same reason they don’t put P rated tires on HD trucks.

[sourdough]

Originally Posted by IHnutz

I am sure this has been brought up here before , but I couldn't find it. My CornPro brand GN flatbed trailer, GVWR =14,000#, came from the factory with LT265/85 R16 load range E tires. That is is size listed on the placard along with the recommended tire pressures of 85#.


I went to buy a new tire and was told "You can't put a "LT" tire on a trailer, it has to be "ST"tire." I asked "Why not?" He answered "Because "LT" means "light truck" and "ST" means "special trailer" and you are putting it on a trailer". I responded "But that is what the trailer manufacturer calls for!" He said " I don't care, you can"t put a truck tire on a trailer."


My question is, Why can't I put a an LT265/85 R16 load range E tire on my GN trailer when that is what the manufacturer calls for?

I am not the resident tire expert. I do know a bit about truck, car, RV, 4x4, swamp, sand, sport and hot rod tires. The question is simply about LT tires on the GN flatbed. The trailer OE tires were LT...and there is nothing wrong with that - the tire shop guy was ill informed.

The further question then became LT tires on an RV. Some do, some don't. Were LT tires meant for an RV? No. ST tires were built and designed for an RV and the use they are put through. Most agree and understand, some like an LT tire and have used them long term with no ill effects - and that's fine for them. Here is a link, from a non tire expert, that has done probably the same kind of research I have and came to the same conclusion. Like what you like, just don't put you, your family or me in danger...

https://www.fateunbound.com/trailer-...t-truck-tires/

[hankpage]

That tire may be a commercial tire rated for Steer/Drive/Trailer. (Three position tires) As long as they meet the load rating required you will be fine. I have used Michilen XPS ribs for years and swear by them. They don't flex like ST tires so they run cooler by design and before some ST tires came with higher speed ratings they had that advantage too. Find a commercial tire service and they will tell you the advantages. Choice of sizes are limited and you won't find them in WalMart. OUR TIRE EXPERTS rarely disagree with what is found on the trailer placard.

If you have been running this type tire for a while you will not like the feel of ST tires or the increase in fuel mileage.
Let us know what you find and whoever told you they were cheap has not priced them. (But worth every penny)

Roll on big wheeler, roll on, Hank

[rhagfo]

I have never had an issue with Discount Tire installing LT tire on a trailer, that is our 5th wheel and my daughter’s two horse trailers.

[CWtheMan]

Originally Posted by IHnutz

I am sure this has been brought up here before , but I couldn't find it. My CornPro brand GN flatbed trailer, GVWR =14,000#, came from the factory with LT265/85 R16 load range E tires. That is is size listed on the placard along with the recommended tire pressures of 85#.


I went to buy a new tire and was told "You can't put a "LT" tire on a trailer, it has to be "ST"tire." I asked "Why not?" He answered "Because "LT" means "light truck" and "ST" means "special trailer" and you are putting it on a trailer". I responded "But that is what the trailer manufacturer calls for!" He said " I don't care, you can"t put a truck tire on a trailer."


My question is, Why can't I put a an LT265/85 R16 load range E tire on my GN trailer when that is what the manufacturer calls for?

Your tire guy was wrong. Tire manufacturers don't' dictate tire sizes, vehicle manufacturers do. The correct replacement tire size is one that will mimic the tire size shown on the vehicle certification label.

However, you're going to have to show me the certification label on your trailer with the tire size before I'll ever believe Keystone put that designated tire size trailer. Besides that, you've listed a tire size not found on discount tire or tire rack inventory.

I found specs for your trailer that listed ST225/75R16 as the original size. They may have changed their mind and used ST235/85R16. Brochures are often wrong and the information on the certification label is correct, unless there was a typo error on the label. If that's the case, Keystone will recall the label and replace it with a corrected one.

[CWtheMan]

Originally Posted by rhagfo

I have never had an issue with Discount Tire installing LT tire on a trailer, that is our 5th wheel and my daughter’s two horse trailers.

Do you take the trailers to the store and have the tires mounted and installed on the trailer? Or do you take the wheel tire assemblies in and have tires installed on the wheels?

Do the certification labels on the trailers depict LT designated size tires?

[rhagfo]

Originally Posted by CWtheMan

Do you take the trailers to the store and have the tires mounted and installed on the trailer? Or do you take the wheel tire assemblies in and have tires installed on the wheels?

Do the certification labels on the trailers depict LT designated size tires?

Took ever one of them to the store, much easier than pulling them and hauling the tires and remounting them.

[IHnutz]

Thanks all, it is just what I suspected all along. The young man at the tire store was "mis-informed"! However, I mis-stated the tire size, they are LT235/85 R16 Load Range E tires. That doesn't change the question of ST over LT tires though. LT tires are what CornPro put on the trailer so that is what I will replace them with. I will just inform the sales person "If you don't what my money I'll just take my business to someone who does!" and drive off. Money talks - BS walks!!


Thanks for the information. I realize this is a forum for RV trailers, not commercial but I knew you would give me a straight answer.

[tech740]

Originally Posted by CWtheMan

Your tire guy was wrong. Tire manufacturers don't' dictate tire sizes, vehicle manufacturers do. The correct replacement tire size is one that will mimic the tire size shown on the vehicle certification label.

However, you're going to have to show me the certification label on your trailer with the tire size before I'll ever believe Keystone put that designated tire size trailer. Besides that, you've listed a tire size not found on discount tire or tire rack inventory.

I found specs for your trailer that listed ST225/75R16 as the original size. They may have changed their mind and used ST235/85R16. Brochures are often wrong and the information on the certification label is correct, unless there was a typo error on the label. If that's the case, Keystone will recall the label and replace it with a corrected one.

He did say this was his gooseneck not an RV. I am guessing that’s why the brochures don’t match.

[CWtheMan]

Originally Posted by tech740

He did say this was his gooseneck not an RV. I am guessing that’s why the brochures don’t match.

His post #13 answers all the questions.

[Stircrazy]

Originally Posted by chuckster57

I’ll wait for the tire guru to answer but I believe the LT tires have a stiffer sidewall among other things. Lots of shops out here will put them on trailers.

Got it backwards Chuck, ST are stiffer sidewalls .

Steve

[hankpage]

Originally Posted by Stircrazy

Got it backwards Chuck, ST are stiffer sidewalls .

Steve

Steve, LT side walls are designed to are designed to flex less. If that translates to stiffer than, Chuck gets the cigar. ST side walls will flex more and squirm more in cross-winds similar to P rated tires on the TV. Now which side wall is stronger I don't have a clue.
Again, the TRAILER manufacturer stated LT on it's placard and they usually have a reason.

[notanlines]

Hank, we’ll pass you a cigar also. Maybe an El Cobre so nobody will come near you.

[Stircrazy]

Originally Posted by hankpage

Steve, LT side walls are designed to are designed to flex less. If that translates to stiffer than, Chuck gets the cigar. ST side walls will flex more and squirm more in cross-winds similar to P rated tires on the TV. Now which side wall is stronger I don't have a clue.
Again, the TRAILER manufacturer stated LT on it's placard and they usually have a reason.

actualy not realy, if you read up on it ST have stiffer sidewalls , yes LT are stiffer than passenger tires but you get better fuel milage with ST tires due to the stiffer sidewall and less chance of them rolling off the bead when doing crazy turns that we subject them to due to the stiffer sidewalls.

if they spec LT tirres I have no problem with that just dont want people thinking its because LT ties have stiffere sidewalls than a ST tire.

persoanly if a trailer has two or more sets of axels I cant see why some one would spec LT tires, a single axel sure, your not going to get the sidewall stresses when cranking it into a site like you do with multiple axels.

there is a couple benifits of the LT tire, better speed rating (ST's are designed as a max 65mph, which is probably why there are so many failures) and better DOT requirments so you get a tire that is generaly a better quality. but a ST tire of the same size will have a 10-20% higher load rating so you may have to go with a bigger LT tire to get the load rating back and you will lose a little bit of fuel milage since LT tires are designed with traction in mine and have a higher rolling resistance than ST tires. another plus is if you just take the rims in and get them mounted and not tell them its on a trailer you can get flats fixed under a road hazard warenty.

Steve

[wiredgeorge]

Originally Posted by Stircrazy

actualy not realy, if you read up on it ST have stiffer sidewalls , yes LT are stiffer than passenger tires but you get better fuel milage with ST tires due to the stiffer sidewall and less chance of them rolling off the bead when doing crazy turns that we subject them to due to the stiffer sidewalls.

if they spec LT tirres I have no problem with that just dont want people thinking its because LT ties have stiffere sidewalls than a ST tire.

persoanly if a trailer has two or more sets of axels I cant see why some one would spec LT tires, a single axel sure, your not going to get the sidewall stresses when cranking it into a site like you do with multiple axels.

there is a couple benifits of the LT tire, better speed rating (ST's are designed as a max 65mph, which is probably why there are so many failures) and better DOT requirments so you get a tire that is generaly a better quality. but a ST tire of the same size will have a 10-20% higher load rating so you may have to go with a bigger LT tire to get the load rating back and you will lose a little bit of fuel milage since LT tires are designed with traction in mine and have a higher rolling resistance than ST tires. another plus is if you just take the rims in and get them mounted and not tell them its on a trailer you can get flats fixed under a road hazard warenty.

Steve

Just a bit of a correction; my Carlisle Radial Trail HD ST225/75R15 LRE are rated for 81 mph by the manufacturer. I typically don't drive 81 mph but do see 65 mph regularly.

https://www.carlislebrandtires.com/o...dial-trail-hd/


This what etrailer.com says about ST VS LT tires:
Light truck tires are a type of passenger vehicle tire and as such they are not built with as thick of a sidewall as trailer tires. A thicker sidewall allows a trailer tire to handle more vertical load. ... Because trailer tires have a thicker sidewall they can build up more heat when under inflated.