G rated (S637) Sailun Tires Thread

[mazboy123]

It seems that there is another G rated (S637- 235/85-16) tire out there that some 5th wheel owners are starting to look at and buy.

They are about $1000 less expensive than the Goodyear G614.

I guess I'd like to start a thread specifically for those who have or will be buying Sailun G rated tires.

I figure we need to start somewhere to get some input on these tires.

[bsmith0404]

There are several threads and posts on this tire already. Many members have posted pictures of them mounted as well and discussed prices. If you would like to consolidate the information in this thread maybe the moderators would be willing to do that for you or you could use the search and copy and paste a lot of the posts here.

[Cyncwby]

I've got a set of the S637's and love them, I've posted on here before about them and got called on it because they state on the sidewall to use a 6.5" wide wheel...... which in fact it does. I think most of the 5th wheel rigs have 6" wide aluminum wheels which of course have to be rated for 110 psi.

The problem was the width so I called several dealers and a few local truck tire installers. The general concenses was yes it should be run on a 6.5" wide truck wheel .... for a truck carrying a very heavy load but for a 5th wheel the 1/4" on each side should not pose a problem.

So far it hasn't, these tires are REAL tires, the POS GY Marathons I took off my rig weighed 36 lbs each, the Sailuns weigh 62 lbs. each. You want peace of mind when towing? Get the Sailuns, get on ebay, type in Sailun S637 and look for a vendor going by "Rustybore", I paid right at $800 shipped to the house.

[notanlines]

Tire King in Fort Myers, Florida. $707.00 including mounting and steel stems. I'm certainly not saying they're better then GY Marathons, but they are great tires. But if you believe you're saving $1000 you're shopping at the wrong dealer.

[CWtheMan]

Sailun is manufacturing two tires in that basic dimension and some even have had the same name and number on the sidewall. Sailun has not yet updated their web pages to identify the two different tire designs. One is the LT235/85R16G rated at 3750# @ 110 psi and the other is the ST235/85R16G rated at 4080# @ 110 psi. A visual inspection is recommended before purchasing either design.

Both designs are rated at 75 MPH.

[Barbell]

Replaced the Marathons last spring at about 25000 miles. One GY was separating and another looked bad but had no trouble with them. The Sailuns came from Big O at about $800 for the set (didn't replace the spare yet). I run 110 psi and they seem to hold pressure well. Also, I think the trailer pulls a little easier at the higher pressure. Tires are on a 2014 Montana 3100RL.

[dcg9381]

Got mine at SimpleTire.com...

[sptddog]

Just ordered mine Friday from simpletire.com for 768 shipped (for 5). It is correct that there are two types suddenly - one is the LT, one is the ST. I couldn't find the LT anywhere, and one dealer said they couldn't get sailun at all until November. Online research indicated that the only difference between the two is that the ST is actually rated a bit higher with a 129L versus the 126L of the LT tire. The rep at Simpletire said the same.

I read on a few RV sites that there is a huge import tax on the LT tires, and so Sailun has changed to calling them ST to avoid the larger import tax. I'm not sure of that accuracy, but that's what I could find. I couldn't find much else, in fact true specs were hard to find, so I took my chances and they should be here next week.

[Cyncwby]

As I've said before, I bought my Sailuns from a dealer named "Rustybore" on ebay for $800 free shipping. So after reading all these price variances I did a little comparison shopping this morning. Rustybore still has them at $190 with free shipping.

Now the Goodyear 614 ...... Amazon $334 free ship ....Walmart $370 free ship ..... Trailer Tire & Wheel $350 unk shipping fee ..... Discount Tire $370 unk shipping fee ......Simple Tire $ 274 + $120 shipping.

There you go, as CW says there are now 2 load ranges, these prices are for the 3750 tire. If you have a really BIG 5th wheel like the old TETON or a tandem toy hauler you might look at the 4000 lb tire. Whichever brand tire you end up buying please get rid of the crappy dangerous tires that come on your rig. Probably the most important buys you'll ever make while traveling.

[dcg9381]

I found that when I ordered from SimpleTire and sent them to a business address of an "installer" it cut the shipping costs in half...

Tires are one thing that I don't worry about now...

[keef95]

I bought a set of seven last spring for my 384PK and have to say I love these tires. 6000 miles and I can see no sign of wear. Aside from an incredibly stiff carcass, the fact that they're a 14 ply and run higher pressure, they just plain roll easier too...

[bobbecky]

I just found the recent Sailun product sheet online at http://www.sailuntires.ca/MRT/S637.html , and they show two different S637 tires, both ST and both with the same weight specs, but one is an 80 series and the other is an 85 series tire, and they are both specifically intended for trailer use.

[dcg9381]

Interesting. I've never found anyone selling the 235/80R16 size, even though that's the factory size of many trailers. Someone post if you manage to find a vendor selling them in that size.

Be aware, if you move up to 235/85R16, you need to have adequate top-of-tire to deck clearance. The diameter change is only 1", but on trailers like the Carbon, the deck-to-tire clearance is lower than most. The result on our trailer is that they're closer to the deck than I'd like - I'm probably going to have to adjust height to be 100% sure we're OK.

I love these tires, they weigh almost twice what the factory tires do...

[jlarocca]

I need new tires for my rig as I'm obviously putting more stress on the E series than I should. I feel like I have a black cloud over me when it comes to trailer tires. I'm interested in the Sailuns but I guess my main concern is what do to if I do have a problem with them. I have had two GY Marabombs blow out and as much of an inconvenience it was GY claims was easy to deal with and paid every cent of my repair. That's the main reason I'm thinking of paying $1000 more for the GY G Series Tires. Would be curious as to how one would go about filing a claim with the Sailuns. It does state in the Sailun warranty:

LEGAL RIGHTS
To the extent permitted by law, SAILUN and its servicing agents shall not be
held responsible for any of the following:
• Commercial Loss.
• Damage to or loss of property other than the tire itself.
• Incidental, indirect, special or consequential damages arising from any
cause whatsoever, including negligence.
No implied or expressed warranties are extended beyond the time when the
tire has delivered its original tread life, except for the expressed warranties
set forth in this “Limited Warranty”. All warranties, promises and agreements,
whether expressed or implied, of merchantability or otherwise, are excluded
to the extent permitted by law. No representative or dealer has authority to
make any representation, promise, or agreement on behalf of Dynamic Tire
Corporation except as stated herein.

[dcg9381]

As I understand it, TBC imports Sailun.

TBC owns Tire Kingdom, NTB - National Tire and Battery, and Merchant's Tire and Auto Centers, depending on your geography.


In other words, I *think* you can buy Sailuns one of the TBC brands and have them warrantied out there, so you're not asking some company in China to stand behind their product.

That being said, I haven't read about any actual warranty experience on them.

[notanlines]

Jlarocca, can you show us in the Goodyear warranty where it says they will pay for damages caused by a blown tire? I have never looked, but I'll bet that they covered your damage just to keep things "smooth" and not cause a hassle. By the way, what was the final ticket on your damages that Goodyear sent you a check for?

[JRTJH]

Jim, You are correct in stating that Goodyear doesn't "warranty consequential damage". The link: http://www.goodyearrvtires.com/pdfs/rv_warranty_610.pdf

Here's their "Items not covered" list:

WHAT IS NOT COVERED UNDER THIS
LIMITED WARRANTY?
• Wear conditions or tire damage due to:
Road hazards (including punctures, cuts, snags,
impact breaks, etc.). Wreck, collision or fire.
Fast wear, irregular wear, heel and toe wear or
other wear conditions.
• Improper inflation, overloading, high-speed
spinup, misapplication, misuse, negligence,
racing, chain damage, or improper mounting
or demounting.
• Mechanical condition of the vehicle.
• Chip/chunk conditions on tires intended for
highway service.
• Ride disturbance after the first 2/32" (inch)
treadwear or due to damaged wheels or any
vehicle condition.
• Any tire intentionally altered after leaving a
factory producing Goodyear tires to change its
appearance (example: white inlay on a black tire).
• Tires with weather cracking which were purchased
more than seven (7) years prior to presentation for
adjustment. If you have no proof of purchase date,
tires manufactured seven (7) or more years prior
to presentation are not covered.
• Material, such as tire fillers, sealants or balancing
substances, added to a tire after leaving a factory
producing Goodyear tires. If the added material is
the cause of the tire being removed from service,
the tire will not be adjusted.
• Any Goodyear Commercial tire with the word
“Mileage” on the sidewall.
• Tires removed from service due to improper repairs.
• Loss of time, inconvenience, loss of use of vehicle,
incidental or consequential damage.
This limited warranty is applicable only in the
United States and Canada.

[jlarocca]

It was close to $7K. I had a marabomb blow about 10 minutes after I left Destin on the way back to Arkansas in August 2014. Had it replaced in Pensacola and the other 3 tires inspected for bubbles, warps, anything suspicious and they looked fine. 50 Miles later and after I went through a weigh station to check to make sure I was not overweight I blew another one on the other side. I stopped in Hattiesburg and replaced the whole set with the only ones I could get which were Hi-Runs. I just had to replace one of those with a huge bubble on the inside side wall (no scuff marks). I'm planning on going out west next year to Grand Canyon and Colorado and before I do I'm upgrading my tires. The local RV dealer told me that he's been doing a lot of wheel and tire upgrades because the E Rated tires are just not cutting it on these larger RV's and Horse Trailers which are very popular where I live. I did just look and found out my wheels are as some stated above rated for 110PSI and 3750lbs.

It just amazes me how much tire trouble I've had on this unit. The tires are not wearing funny at all so I don't believe my alignment is bad. Before this rig I had a 40' Royals International that weighed a whole lot more than this one but was a triple axle. I ran Firestone FR480's on that one that I had pulled off my dually. Had one tire issue where I had a zipper tear in the sidewall but no damage to the unit. Nothing like the major explosions I've had with this Montana. Keeping fingers crossed that upgrading load rating will be the last of my issues.

Jlarocca, can you show us in the Goodyear warranty where it says they will pay for damages caused by a blown tire? I have never looked, but I'll bet that they covered your damage just to keep things "smooth" and not cause a hassle. By the way, what was the final ticket on your damages that Goodyear sent you a check for?

[dcg9381]

Jim, You are correct in stating that Goodyear doesn't "warranty consequential damage".

My bet, when they're replacing the tire due to "defect" that that their terms and conditions doesn't actually do much to release liability.

It's essentially like saying we're not responsible for a defective product. You can't just opt out like that, although it might be effective with many consumers at face value.

The real question with really any product from China is who will stand behind it.. In the Sailun case, my guess is that it's TBC - especially if they sell and mount the tires.

[NotyetMHCowner]

I just paid $462 for 4 Sailun S637 LT235/85R16G tires out the door at NTB in Knoxville, Tn. $83.50 for the tire plus taxes, mounted, balanced, etc. I inquired about a 5th for my spare and he said he can get it in within 2 days because he is showing 80 in two different locations at his warehouses. Our camper is getting warranty work done so I cant get them mounted yet until we get it back home. I about flipped when he told me the price this morning on the phone. I though he had made an error. I still didn't believe it until we loaded them in the truck and I was pulling away!

If I am reading the date code correctly, looks like they are 17th week of 2014, so maybe they had them in stock since then and reduced the price to move them, I don't know. But he said he would honor this price for the spare if the price went up.

[dcg9381]

Still loving mine, unless I have to remove them (they weigh a ton). Turns out I should have gone with the 80-series, instead of 85s... Just haven't seen them advertised..

I see that they are warrantied by TBC corp - which owns NTB.. Basically a nationwide US-based company.

[sw342]

I love those tires. Anyone still running ST tires on a heavy trailer when there are other options available is just pushing their luck.

[CWtheMan]

A lot of the Forest River RV trailer line-up for this year are using OEM tires from Westlake. Here are a couple of pictures I took of ST235/85R16G tires on a FR fiver with 7000# GAWR axles.

Westlake also manufacturer’s the LT235/85R16G tires.

Like all steel cased tires of this size the 16x6.5” rim is standard. Both sizes have an Inflation pressure of 110 PSI to get to the tire’s maximum load capacity.

Note that the OEM provider has serviced the tire in the picture with 100% nitrogen as identified by the green valve cover.

The pictures were taken of a spare I found in the forward cargo compartment. The tires on the trailer had aluminum rims.

All new ST tires this year will have speed ratings. These have a letter L = 75 MPH.

http://www.irv2.com/photopost/showfull.php?photo=29711

http://www.irv2.com/photopost/showfull.php?photo=29709

[NotyetMHCowner]

I think my rims are only 6", but it will just have to work for now. I will probably run less than the maximum 110psi, but not sure what pressure as of yet.

[CWtheMan]

Just a couple of notes.

If you call a Goodyear light truck tire representative they might say another rim width will work for the G614 tires. If you email them they will say only the 6.5" wide rim is appropriate. I've done both. They will only put 6.5" in writing.

Tire industry standards for replacement tires will tell you to use the amount of tire inflation pressure necessary to provide, at the minimum, the load capacity of the Original Equipment tires listed on the federal certification label. Anything less than that would be considered under inflation.

[Barbell]

We put on the Sailuns last summer after seeing how close to failure the original Goodyear Marathons were. Never had a problem with the GYs but maybe it was just luck. Anyway, we have pulled the rig a little over 6000 miles with the Sailuns and I think it pulls easier with the higher inflation level. The main thing I like is that they show no wear at all so far and they hold air pressure right on the money. I check the air and lugs bolts before each departure and even though I carry an air compressor, I have not had to use it so far since putting the Sailuns on. Ours came from Big O Tire so I will look to them if there is ever a problem.

[roadglide]

I love those tires. Anyone still running ST tires on a heavy trailer when there are other options available is just pushing their luck. Yes with 10000 miles on them and starting to show wear dated 6/14. I'm going with LT G tire from Good year before my next trip to Big Bend texas next month.

[roadglide]

Interesting. I've never found anyone selling the 235/80R16 size, even though that's the factory size of many trailers. Someone post if you manage to find a vendor selling them in that size.

Be aware, if you move up to 235/85R16, you need to have adequate top-of-tire to deck clearance. The diameter change is only 1", but on trailers like the Carbon, the deck-to-tire clearance is lower than most. The result on our trailer is that they're closer to the deck than I'd like - I'm probably going to have to adjust height to be 100% sure we're OK.

I love these tires, they weigh almost twice what the factory tires do...

Big O dealer said 1/2 inch higher because i'm running the 80 /16 and will need to go with 85/16. with G LT tires.

[CWtheMan]

Still loving mine, unless I have to remove them (they weigh a ton). Turns out I should have gone with the 80-series, instead of 85s... Just haven't seen them advertised..

I see that they are warrantied by TBC corp - which owns NTB.. Basically a nationwide US-based company.

Guess who the big owner is? It's in the ref..

http://sumitomotire.com/news.aspx

[williams19740]

We purchased these G load tire for our 3750FL and could not be happier. Towed back from Florida(had the tires shipped down there) and they performed perfect. Tire pressure monitor showed 110 degrees towing on highway at 75 in 90+ degree heat. If your gonna run a tire monitor i would highly recommend using Ford Dually OEM steel vavle stems. They have worked amazing. I broke 2 other stems from other bolt in types and found the Ford OEM for dually work excellent.

[dcg9381]

Guess who the big owner is? It's in the ref..


I think you're saying tht Sumitomo is the actual owner, as they bought TBC in 2005. I didn't know that.

TBC is more commonly known as:
Carroll Tire Company
Tire Kingdom
National Tire & Battery (NTB)
Treadways



In terms of actual diameter, 235/80 to 235/85 is actually .9 inches. So everything else being the same, you get .45" lift. However, these tires have massive tread depth, it wouldn't surprise me if actual measurements were more significant than that. I assumed that the size difference would be fine, but now I'm looking at lifting my trailer to get back some tire-to-deck clearance....

[NotyetMHCowner]

Finally got my Sailuns mounted and balanced today. When I bought them, NTB had them in their store for quite some time. They are a little over a year old. They were still the LT variety, and only $83.50. I ordered a fifth tire for the spare and asked at the time if the price would be the same. I was told yes. So when I was at the store today, the tire is an ST tire and came up at $172! After a little arguing, I got it for $83.50, plus I used a $10 off coupon that was attached to my first invoice from buying the first 4. They are beefy and heavy. I dropped the pressure down to 90 psi. Im not sure how much pressure I will end up running. That is like asking what brand truck to buy and which is the best oil to put in it!

[roadglide]

I think you're saying tht Sumitomo is the actual owner, as they bought TBC in 2005. I didn't know that.

TBC is more commonly known as:
Carroll Tire Company
Tire Kingdom
National Tire & Battery (NTB)
Treadways



In terms of actual diameter, 235/80 to 235/85 is actually .9 inches. So everything else being the same, you get .45" lift. However, these tires have massive tread depth, it wouldn't surprise me if actual measurements were more significant than that. I assumed that the size difference would be fine, but now I'm looking at lifting my trailer to get back some tire-to-deck clearance....
That is correct after talking with a dealer from discount tires. Im pushing 10000 miles on my trailer kings . Im now looking for Sailun 235 /80 or 85 16 . This has been a good open thread .

[dcg9381]

Let me know if you get them in 80-series...

[roadglide]

Big O is 1 1/2 mile from my dealer and they only have the 85 in the G ply. they quoted me 780$ out the door. that tire would at the most 6 week dated. I have 5 inch between the tires now , that would put me at 4 inches between the tires mounted on the fifer with the 85. I think that is acceptable.

[dcg9381]

Watch the distance to the deck too - that's what got me.

[CWtheMan]

Big O is 1 1/2 mile from my dealer and they only have the 85 in the G ply. they quoted me 780$ out the door. that tire would at the most 6 week dated. I have 5 inch between the tires now , that would put me at 4 inches between the tires mounted on the fifer with the 85. I think that is acceptable.

All steel cased tires in your size have a single approved rim width. Look at post #23.

Here is a picture. http://www.irv2.com/photopost/showfull.php?photo=29709

[roadglide]

All steel cased tires in your size have a single approved rim width. Look at post #23.

Here is a picture. http://www.irv2.com/photopost/showfull.php?photo=29709
I will check that out, it seem that a fifer with 16000 GVW and 7000 lb axles that the rims would be approved for G raited tires.

[CWtheMan]

I will check that out, it seem that a fifer with 16000 GVW and 7000 lb axles that the rims would be approved for G raited tires.

I was looking at the Keystone spec page for your trailer and can’t get the numbers to work.

Here is what they have;

GVWR: 16,500#
Cargo: 4,860#
Hitch : 2,780#

To calculate GAWR for two axles you subtract the hitch weight from the GVWR and divide by two (6860#). That is more than the minimum load capacity for the ST235/80R16E tires (3420#)

Does your certification label and cargo capacity figures differ from the ones above?

Is there a notation in your owner’s manual or on any of the tire labeling to inform you to use ST235/80R16E tires with load capacities of 3500# or above? If not and your labeling matches the figures I used above the OE tires fail the axle’s minimum safety requirements the manufacturer has said it passed.

If my info is correct it’s a simple fix for Keystone. All they have to do is lower the cargo capacity and GAWR values and issue an updated federal certification label. They can also say there was a typographical with the published hitch weight and then change it to fit the situation.

There is another way Keystone could have set your trailer’s GAWRs to 7000#. It’s a letter of compliance and they have to send it to NHTSA showing they used those ST tires that are manufactured with load capacities at or above 3500# on the axles. They would also have to provide the consumer (you) with a copy of such communications to add to the vehicle owner’s manual.

Keystone knows all that stuff because they have had a number of certification recalls for similar discrepancies.

But, just maybe, the information on your trailer’s labeling is more accurate than the historical specs.

[roadglide]

Right on with the hitch weight. The fifer has been on the cat scales 3 times . The last trip to Quartzsite loaded with harley and Quad in the garage the was like 11400 on the trailer axles with some fresh water. way under the 14000 lb axles and the 3520 lb load for the tires 14080 new. Tell you the truth. I have 10000 miles on the trailer Kings and they look very good. I'm pulling the trigger on some saline tires tomorrow if big O approves them for my fifer.

[Titan Guy]

All tires have an optimum rim width. In the LT235/85R16 that is 6.5".

Tire & Rim Association list approved widths of 6.0", 6.5", & 7.0".

[On The Road Again]

I grew tired of the uncertainty of the Trailer King tires, even though they had only about 4000 miles on them, and ordered a set of Sailun ST235 80R16. Dropped it off Tuesday morning for the swap out. Came back by about lunch time and this is what the shop wanted to show me. I am diligent about my tire maintenance including checking pressure, temp, watching my speed and visual inspections at stops. I also have the TST 507 TPMS. This bubble was on the inside and I failed to catch it and had just come home from a short trip. Let this serve as your official warning to get rid of those "china bombs."

[dcg9381]

Claim that sucker, see if you can at least get some money for it. I'd press for "all" tires, actually.

Also file a complaint. Trailer King seem to be a rebrand of another tire with a crappy reputation. Help get these on record as bombs that consumers should be wary of:

https://www-odi.nhtsa.dot.gov/ivoq/Complaint.cfm

[roadglide]

I kicked around st or LT tires . I just got the 235/85/16 sailun installed today they set my toy hauler up higher then expected but there is 3 inches all the way around the wheel wells and tires , going from a 280 to a 285 I was a little concerned with spacing no problem there. The trailer Kings did there 1 year worth of traveling , I was never comfortable with the softer tire from trailer king.

[dcg9381]

3" of clearance prior to the new tires would give 2.5" or so - that's too tight for my comfort level on the deck - looking at a 1" lift to get it back to where it was.

In hindsight, I should have gone to 235/80-16s.. Which Sailun also makes - I just couldn't find them at the time.

[CWtheMan]

All tires have an optimum rim width. In the LT235/85R16 that is 6.5".

Tire & Rim Association list approved widths of 6.0", 6.5", & 7.0".

Do you have a TRA manual? If so, look at that size with the steel casing design. It's 6.5".

Although not required, some manufacturers put the 6.5" rim requirement right on the steel cased tire's sidewall.

http://www.irv2.com/photopost/showfull.php?photo=29709

[roadglide]

That was just eye ball guess. I went out with a yard stick and there is 4 inches after the 285 installed. To close for comfort is rubbing tires or wheel well, the tires cant go any where unless they fly apart or rubbing. On my duramax there isn't a inch from the front tires and wheel well. One more thing the 280 tire is just a odd ball size they through on these heaver toy haulers.

[Koladog]

Just got a set of Sailun S637 ST235/80R16 installed on my Mountaineer. They are more than enough tire for this trailer (11,000 lbs dry). The tire guys pumped them up to 80 lbs as stated on the placard. Just wondering if I should leave them there, pump to max 110 lbs, or somewhere inbetween???

[gearhead]

Just got a set of Sailun S637 ST235/80R16 installed on my Mountaineer. They are more than enough tire for this trailer (11,000 lbs dry). The tire guys pumped them up to 80 lbs as stated on the placard. Just wondering if I should leave them there, pump to max 110 lbs, or somewhere inbetween???

Look on the back of the wheel and see what it is rated for...either weight or pressure. If what has been posted here is correct, Sailun can be run at less than max air pressure, dependent on the load on the tire.
Don't just air up the tire over 80psi not knowing what the wheel is rated for.
Do a search on here for Sailun and find the post with the email from Sailun regarding running less than max air.
From memory, and please don't take this to the bank, I think Sailun says you are OK to run the tires at 80psi if loaded no more than 3,000 pounds per tire.
You should weigh your 5th all loaded and "ready to go".

[Koladog]

My wheels are rated for 110PSI. On our last trip our fully loaded trailer weighed in at about 12,800 lbs (just trailer).

[CWtheMan]

Just got a set of Sailun S637 ST235/80R16 installed on my Mountaineer. They are more than enough tire for this trailer (11,000 lbs dry). The tire guys pumped them up to 80 lbs as stated on the placard. Just wondering if I should leave them there, pump to max 110 lbs, or somewhere inbetween???

If your tire placard says 80 psi you already had ST235/80R16E tires. The Sailun LRG is also a ST235/80R16 and at 80 psi will provide the same load capacity as the OE tires. They will be a little more durable but not stronger when inflated to 80 psi. To gain much needed load capacity reserves from your new tires you should establish a new recommended inflation pressure for them.

[Titan Guy]

I have sold 100's of Sailun Tires and have yet to see a single complaint.
On most trailers you want max air pressure that the tire & wheel will handle. Reason is you want reserve load capacity of 20%+ on your trailer tires, just like you have on your pickup, passenger and SUV tires.
A load range G with a 3,750 load capacity would have 20% reserve capacity with a tire load of 3,000 lbs.

[CWtheMan]

Trailer tire inflation pressures are an often pondered subject in RV trailer forums. Often times getting overheated. The discussions roam from wants to needs or what is correct as opposed to what is thought to be correct.

During the trailer’s certification process NHTSA via FMVSS directs the trailer manufacturer to set the recommended cold tire inflation pressures. Those pressures are the correct pressures and are the standard from which all subsequent replacement tires will get their inflation pressures from. Industry standards do not say you cant use more than what is recommended if you have some to use and the rims have the necessary load capacity and increased pressure values to sustain higher than recommended inflation pressures. However, Industry standards will not recommend any pressures lower than what has been recommended by the vehicle manufacturer for Original Equipment (OE) tires.

Even though the same regulation (standard) is used for tire inflation on motorized vehicles and RV trailers there are differences. Motorized vehicles must have reserve load capacities via inflation. TV trailer tires do not.

The simplest way to say this is as follows: Replacement tires must be capable of providing an equal or greater load capacity (via inflation) than the OE tires. This is normally where the confusion sets in when using replacement tires of another size or design and size. What to inflate them to. The tire placard gives the answer. Remember, you must equal the load capacity of the OE tires. So you use an inflation pressure that does just that, or more, for greater reserve load capacity as long as the rims are qualified for the tire fitment.

Auxiliary tire placards are authorized for the plus sized tires. You just make one up showing the new tire size and recommended inflation pressure and place it next to the original placard. Then go and make notations in the owner’s manual.

There is no official figure for tire reserve load capacities for RV trailer tires. The RMA has always recommended 12-15% but has never been able to get the rules makers to make it official. Whenever an owner wants an extra 15% load capacity reserve it's normally going to cost more than expected because new rims will also be needed. Even if the industry starts doing it there will have to be a phase-in because of the trailer design elements that will have to be changed.