Replacing 7-Year-Old Sailun S637 Trailer Tires

[Maggiesclan]

Hello all,
My wife and I purchased a 2020 3120RL SAILUN S637 (235/80R16)tires are original with date code (1919). I realize the tires are 7 years old. The history of use shows aprox 2500 miles since tires were new.

My tire shop manager, who I trust, told me that we would be glad to sell me a set of tires but said if it were him he would continue using the Sailun tires currently on the rig.

I asked the shop manager if he could order Sailun S637’s. He can get them for $179.00 each but they will be shipped from east coast to my home north of Seattle, WA.

MANAGER asked about getting freshly manufactured tires and was told by person on east coast that there was NO guarantee as to how recently the tires were manufactured. Manager also told me that tires would not be refundable due to requirement that they be returned to east coast, if they have sat on a rack for a while.

NOTE: If I purchase at my local tire shop, they shop would honor warranty under their guidelines. I was told if I purchase from another source, my tire shop would mount/balance tires but would not be able to provide warranty protection.

Your opinion on whether to purchase Sailun tires from my shop (that may have been manufactured a while ago) vs going with another brand of tire such as:

Rainier ST ASL (all steel belted)
** I have read mixed reviews on Rainier brand

*I would buy Sailun’s right now if I knew they were freshly manufactured. If they were let’s say a year old but new, would you consider running them 5-6 years?

Sorry for lengthy message. Your input would be appreciated!

Thanks,

Seán

 

[Carl n Susan]

Seven years is realy pushing it for RV tires. I don't know how you verified the RV only went 2,500 miles in six years, but it seem very unusual,. But UV and tire rot do more damage to a tire than mileage. You can get Sailuns from a number of providers = America's Tire/Discount Tires, Les Schwab, Big O, Simple Tire, Walmart, Amazon, and on. All of whom have a presence across much of the USA.

I last ordered a Sailun from Amazon and it arrived with a two year old date. I called Customer Service who agreed that was too old. They sent another tire (under six months old) and paid for the return of old tire.

Taking a chance on tires is not a risk you want. When they go, they take a lot of expensive to repair things with them

 

[LeftOverParts]

The Sailun website shows they have an 8 yr mfr warranty but the consensus here and other rv discussion boards seems to be 5 yrs. We’re in the market too and although not the lowest price, I’ve got ST235/80 16 (G) on order from Walmart at $215 each incl tax/delivery with 90 day return policy. I went with WM for an easy return in case the tires are older than I’m comfortable with.

I found a well known online shop that would be a little less but never have purchased from them. I called and the customer service rep mentioned their tires could be 2 yrs old but stored properly.

Folks may differ but I’m taking the age as worst case away front the 8 yrs so 2 yrs old is 6 yrs with a 1 year “safety factor” is 5 yrs. Hopefully those WM tires are much less than 2 yrs old.

Here’s a recent discussion on new tire age and G vs H rating.

Finding Fresh Sailun H-Rated Trailer Tires

Well I attempted to buy a new set of Sailuns , have yet to find a set thats any newer than just over a year old ,and that is the H rated . the G rated was over two years old . :oops: Got another local tire shop looking for a set ,would prefer local . Price is actually better locally than...

www.montanaowners.com

(I’m sticking with the G since they’ve worked for us and we run slightly less than 110 psi max pressure since we don’t load the trailer to max GVWR.)

Picture from Sailun website showing 8 yrs. I not saying go 8 yrs and wouldn’t go close. As mentioned you could have age wear (even though the tire looks good) and blowing a tire can create a major headache during a trip with damage to the trailer, delays in remote places, missed reservations. Folks here have described damage cost exceeding the cost of a new set of tires.

(Remember to address your spare even thought it’s probably been tucked under the trailer all this time.)

 

[ChuckS]

If it were mine the tires would be replaced at the end of 7 years max... I have run the last two sets of tires for 7 years each... First set was GeoMax from Les Schwab, Second set is Sailun S637..

** I would upsize your tires to ST 235/85x16... more load capacity rating... tire height increase is 1/2 inch.

The "old school" adage was every 3 years no matter what... Tire construction has changed over the years...

A bit of tire info:

Tire aging .. this is interesting ( Created with help of AI )​

Short answer: No — a Sailun S637 (or any tire) generally ages slower in a warehouse than when mounted on an RV, even if the RV tires are covered. But the difference depends a lot on storage conditions.

Here’s how it works.

⸻

1. Tires age even if they are never used

Rubber compounds slowly change over time due to oxygen, ozone, heat, and UV light. These cause oxidation and chemical changes that make rubber harder and less elastic. 

So a tire does age in a warehouse, but the process can be slowed dramatically if the environment is controlled.

Typical guideline:
• 0–5 years: considered normal usable age
• 5–10 years: inspect carefully each year
• 10 years: most manufacturers recommend replacement regardless of tread 

This applies whether the tire is used or stored.

⸻

2. Warehouse storage usually slows aging

A properly stored tire (like a new Sailun S637) typically sits in:
• Cool temperature
• No direct sunlight
• Low ozone exposure
• Minimal temperature swings

These conditions slow the chemical aging process. 

Because of this, it is very common for new tires to be 6–24 months old when sold, and still considered “new”.

⸻

3. RV-mounted tires age faster even if covered

When installed on an RV, several additional factors accelerate aging:

Heat cycles
• Driving flexes and heats the tire carcass.

Internal oxygen
• Tires are inflated with air (~21% oxygen), which slowly oxidizes the rubber from inside.

Sun, ozone, and weather
• Even with covers, some UV and ozone exposure occurs.

Static load
• RV tires often sit loaded in one spot for long periods.

These conditions can accelerate aging compared with controlled storage. 

⸻

4. A surprising RV reality

With RVs, age usually kills the tire before tread wear does.

Many RV tires fail with plenty of tread because UV, ozone, and time degrade the sidewalls. 

⸻

Practical takeaway for your Sailun S637:
• A tire 2 years old in a warehouse may actually be in better condition than a 2-year-old tire mounted on an RV outdoors.
• The key number is the DOT date, not the installation date.

⸻

For RV owners (especially heavy trailer tires like the S637):

Most experienced RV techs recommend replacing around 5–7 years from the DOT manufacture date, even if tread looks good.

EMAIL I received inquiring about tire age and the ST637 G rated (14 ply) tire:
Chuck,



We are in receipt of your inquiry. We are a wholesale tire distributor of multiple brands of tires, not a tire manufacturer, and we create dedicated websites for each of the brands we distribute; we distribute the Sailun brand of tires in the USA.



The Sailun S637T in a 16-ply rated capacity was introduced last year and the 14-ply rated was discontinued; therefore, you could see date codes on these tires from late 2024.

Although there is no expiration date on tires, as a distributor, we do not sell tires that are 6 years old or older, as these will be considered old. A tire is considered new if it has never been installed, regardless of the date code.

If you do need a tire that can carry more than the maximum load on the 14-ply rated, there may not be any benefits to upgrading to 16 ply rated. The 14-ply rated tire has a capacity of 4,400 lbs. per tire in a single application and 3,860 lbs. per tire in a dually application; maximum psi is indicated at 110. If you are running your tires at 95 psi, the load inflation chart provided by Sailun indicated that the maximum load is 3,970 lbs. per tire in a single application and 3,525 lbs. per tire in a dually application. A 16-ply rated tire run at 95 psi will definitely be a rougher ride.

As for what date code can be seen on new tires when purchased vary greatly. It all depends on how often your tire dealer purchases that tire from their Sailun distributor and the same applies to that Sailun distributor, how many tires they purchase and keep in their warehouses to supply to their customers.


Thank you,

Olga Fraga
Consumer Relations
TBC Wholesale
Tel. (800) 238-6469
Fax. (800) 467-4638
ofraga@tbccorp.com

** Bottom line for my use: I kow how the tires are maintained when not towing ( covered and air pressure maintained at 95 psi cold...

.. I dont make long trips anymore ( max one way distance about 400 miles )
.. I tow at 62 mph
.. I DO NOT tow in hot weather ( max outside air temp ) for us is 80 degrees

** I have no issue running a set of Sailuns for 7 years but monitor the tire appearance closely each year of use....

** I DO NOT like Rainer tires but would install these other two tires if Sailuns were not available:
>> Hercules Strong Guard - the H901 series has been discontinued
>> Carlisle CSL series

YMMV

 

[twindman]

I had 2 ties blow out on one trip in 2023. I checked my records and couldn't find anything on tire purchase. I was pretty sure they were only 3-4 years old and looked new. I was driving from Cody to Phoenix area. First one went in the Rawlins area. Got a new spare and mounted it. Continued on home and 2nd one blew 20 miles from home. It was 110-115. Not quite enough room to pull completely off the freeway!! Call tow company and they said since I wasn't completely safe, call 911. An AZ highway person showed up in 5 minutes and got my tire changed.
$9500 damage - my share only $500. I checked the date code on tires. 3 were 5 1/2 years and one was 6 1/2 years old!!!
So when tires are 5 years old from manufacture, I am buying new tires!!!

 

[mlh]

Twindman
This story reminds me of a trip to Wyoming. My brother with 2 friends and I were on I80 on the mountain before Laramie when we lost our second tire. Now what to do. We limped 20 miles to Laramie spent the night at Walmart. We had a friend in Laramie who took us to buy mew tires. Good to have friends in high places. The elevation in Laramie is 7200 feet.
Lynwood

 

[DutchmenSport]

Check into Hercules tires. I've been running Hercules on my High Country for many years now. I've had good success. The only problem was a bent axle once, and a tear on another one when I did a bad skid on a concrete curb. Hercules has a good reputation. That's my recommendation.

 

[St. Michael]

I have Saluns on my RV because that’s what came on it and I like them but I have Hercules on our horse trailer and my Silverado and really am happy with them. Might have to flip a coin when it’s time to replace the Saluns

 

[LeftOverParts]

and the 14-ply rated was discontinued; therefore, you could see date codes on these tires from late 2024.

Ugh, means 18-24 months “old” at best. I’ll post what comes in and if we trade up to H’s.

A 16-ply rated tire run at 95 psi will definitely be a rougher ride.

One of the reasons I prefer a G rated tire. Our trailer weighs in about 15,300 lbs with 3,100 lb pin. Each tire then carries 12,200 lbs/4 =3,050 lb per tire. That’s about 900 lbs per tire under the load rating.

(On a different note, we live in SoCal and the temps where we store the trailer run about 85-105 deg in the summer. Whenever we store, we cover the tires and park on a 2x12x5’ board to keep the tires off the hot asphalt. We also cover when staying more than a couple days at hot, sunny places during travel).

 

[twindman]

You might want to use CAT scales to get accurate weight per tire. I parked one time with axles on different sections of scale. Then the second time I did the same but kept one side off the scales. By subtracting the difference you can calculate the other side. Hence weight per tire. And the side with the frig and stove was several hundred pounds higher.

 

[Planenut99]

I just bought 5 Sailun S637 ST235/80R16’s from Amazon. They delivered in about 3 days and are 16 PR. I will note that they are made in Cambodia. The date codes are 3925 through 4125. The price was reasonable and they look good. I’ll have them mounted and balanced locally.

 

[Maggiesclan]

Seven years is realy pushing it for RV tires. I don't know how you verified the RV only went 2,500 miles in six years, but it seem very unusual,. But UV and tire rot do more damage to a tire than mileage. You can get Sailuns from a number of providers = America's Tire/Discount Tires, Les Schwab, Big O, Simple Tire, Walmart, Amazon, and on. All of whom have a presence across much of the USA.

I last ordered a Sailun from Amazon and it arrived with a two year old date. I called Customer Service who agreed that was too old. They sent another tire (under six months old) and paid for the return of old tire.

Taking a chance on tires is not a risk you want. When they go, they take a lot of expensive to repair things with them

Thank you to everyone who posted ref Sailun tire issue. I will be searching for a good deal on Sailun’s!

 

[Minion]

Hello all,
My wife and I purchased a 2020 3120RL SAILUN S637 (235/80R16)tires are original with date code (1919). I realize the tires are 7 years old. The history of use shows aprox 2500 miles since tires were new.

My tire shop manager, who I trust, told me that we would be glad to sell me a set of tires but said if it were him he would continue using the Sailun tires currently on the rig.

I asked the shop manager if he could order Sailun S637’s. He can get them for $179.00 each but they will be shipped from east coast to my home north of Seattle, WA.

MANAGER asked about getting freshly manufactured tires and was told by person on east coast that there was NO guarantee as to how recently the tires were manufactured. Manager also told me that tires would not be refundable due to requirement that they be returned to east coast, if they have sat on a rack for a while.

NOTE: If I purchase at my local tire shop, they shop would honor warranty under their guidelines. I was told if I purchase from another source, my tire shop would mount/balance tires but would not be able to provide warranty protection.

Your opinion on whether to purchase Sailun tires from my shop (that may have been manufactured a while ago) vs going with another brand of tire such as:

Rainier ST ASL (all steel belted)
** I have read mixed reviews on Rainier brand

*I would buy Sailun’s right now if I knew they were freshly manufactured. If they were let’s say a year old but new, would you consider running them 5-6 years?

Sorry for lengthy message. Your input would be appreciated!

Thanks,

Seán

Look at the Hercules H-901 Highway All-Steel Commercial ST.
That is what I installed on my 3660RL. Quite happy. If I recall correctly, they are a Cooper tire product.

 

[Minion]

Thank you to everyone who posted ref Sailun tire issue. I will be searching for a good deal on Sailun’s!

Look at the Hercules H-901 Highway All-Steel Commercial ST.
That is what I installed on my 3660RL. Quite happy. If I recall correctly, they are a Cooper tire product.

Forgot to mention, I’m on the northwest coast and wi tee in AZ.

 

[Maggiesclan]

Forgot to mention, I’m on the northwest coast and wi tee in AZ.

Thanks for tire info Minion!

 

[jkxtreme]

SEven years... time to change, especially if the are sitting most of the time. Don't need to buy Sailun, but really need to buy 'H' rated tires.

 

[Maggiesclan]

Thanks jkx

 

[WhatExit?]

Tire replacement - new to me options ("DIY" to save $$$)

Knowing how important tire life/safety is especially here in the AZ heat, I decided to replace all 5 tires (4 + spare) on my 3120RL. I did my research and determined I'd stay with the Sailun tires. Sailun All Steel Radial Tire S637. Sailun G-Rated tires ST235/80R16G on the 16 x 6 rims. I...

www.montanaowners.com

 

[LeftOverParts]

Updating post #9 above.

WM sent ST235 80 16 H instead of G. Date code 0326. Decided to go with them. Mounted and balanced at Americas Tire (Discount Tire) for $30 each including disposal. Had them inflate to 100psi.

Re balancing, I realize the nut centric balancing thing but went with their hub centric method. I don’t know but thinking a wheel mfr would use a cnc lathe/mill so the OD, hub, bolt holes, and bolt circle would be aligned or aligned close enough. If you know how their made, an explanation would be helpful.

I did ask that they not stack any weight blocks bc the clearance to the disk brake caliper is really small. Checked and they didn’t stack.

 

[Eldergioe]

Just my two cents worth. I have a 2019 3791. I chased the rabbit hole to figure out what tires I wanted to put on it last year and ended up with hercules. Couldn't be more happy with them in the last 2 trips they have only left lost about 2 lb of air. So far they outperform the Sailuns.