110psi tire question...

[garysol]

Not to beat a dead horse but I am a little confused after reading many threads on the subject. I am running the Sailun S637 G rated tire with a max PSI of 110 which is what I have been running. I have read that many many people are running G rated tires at 100 or even 90PSI which lowers the tires max rating. I am confused as to why I would want to lower the inflation in the tire. Why would I not want want as much weight carrying as possible? What is the advantage to running a lower inflation?

[Me_Again]

jadatis wrote:
I am planning to make pressure loadcapacity lists for ST tires .
In that for every pressure in steps of 5 and also 10 or 20 psi over "maximum pressure", a colom of 5 loadcapacity's. At top for 65m/h at bottom lowest load that still gives acceptable grip and comfort.

Are we talking about ST tires here or LT tires.
St tires are calculated in their maximum load for lower speed so more deflection.
If they are LT tires they are calculated in maximum load for 99m/h so lesser deflection.

So my opinion is that for LT tires follow my pressure/loadcapacity lists and add up to 18% to the weighed wheel load first before looking back the load in the list.
but if you have ST tires first calculate the maximum load back to 99m/h .
For this see my topic here
how to compare tires for replacement

And for the extra save pressure loadcapacity lists see next map on my one.drive
Extra save pressure loadcapacity lists

Using this topic and P/LC lists you can determine a highest pressure at wich comfort and gripp is still acceptable and gives as much possible reserve for things like , pressure loss in time, misreadings of pressure scale, mis-yudging of loads on tire, etc.

fmnjmnjoeawhtnaoerltuwe40thng'dsto9user

[jadatis]

I am planning to make pressure loadcapacity lists for ST tires .
In that for every pressure in steps of 5 and also 10 or 20 psi over "maximum pressure", a colom of 5 loadcapacity's. At top for 65m/h at bottom lowest load that still gives acceptable grip and comfort.

Are we talking about ST tires here or LT tires.
St tires are calculated in their maximum load for lower speed so more deflection.
If they are LT tires they are calculated in maximum load for 99m/h so lesser deflection.

So my opinion is that for LT tires follow my pressure/loadcapacity lists and add up to 18% to the weighed wheel load first before looking back the load in the list.
but if you have ST tires first calculate the maximum load back to 99m/h .
For this see my topic here
how to compare tires for replacement

And for the extra save pressure loadcapacity lists see next map on my one.drive
Extra save pressure loadcapacity lists

Using this topic and P/LC lists you can determine a highest pressure at wich comfort and gripp is still acceptable and gives as much possible reserve for things like , pressure loss in time, misreadings of pressure scale, mis-yudging of loads on tire, etc.

[Me_Again]

I put around 40K+ and 6.5 years on the RIBs on my trailer. When I sold them on CL they had about 65% tread left. Never ran them at max sidewall pressure given the 10K+ on them. Lots of hot SW weather also. Chris

[Mile_High]

I personally have never worn a trailer tire out, regardless of the pressure I run - that "old age" thing always gets them first! (ST = 3-5 years, G614 = 5-7 years)

Full timers may have different results, but I've always been safe just running the max cold pressure and not stressing it.

[wandering1]

Nothing to be confused about. The PSI to run in your tires is on the sidewalls of your tires. Running your tires overinflated or under inflated will cause the tires to overheat and damage the tire. If you need more info then contact the tire manufacturer. Do not pay attention to the tire expert wannabes on the forum. Their personal opinion or bad habits is not in your best interest.

[JIMNLIN]

christopherglenn wrote:
I run sidewall max, From my days as an OTR driver, everything gets set to sidewall max every PTI. The single biggest tire issue out there is underinflated tires - which causes them to be overloaded while under their rated load - leading to failures. I can't think of the last time a non recap tire failed without hitting something when aired up properly.

Yeah our LT tires on a trailer with a 10-16 ply rating, can better with stand derating with lower pressures than a ST tire on these size trailers.
When I was on the road pulling trailers I found a tire on a "TRAILER" with max pressure can better with stand carcass damage or sidewall cuts when encountering road debris/sharp sided potholes or simply rolling over a curb/etc, than a tire that has been derated with lower air pressures.

Worked better for me in the long run to stick with a tire with a bit (5-10 %) of reserve and not to over tire a trailer.
Like Michelin truck tire add said;
"max performance and max reliability comes at max pressures"

[christopherglen]

I run sidewall max, From my days as an OTR driver, everything gets set to sidewall max every PTI. The single biggest tire issue out there is underinflated tires - which causes them to be overloaded while under their rated load - leading to failures. I can't think of the last time a non recap tire failed without hitting something when aired up properly.

[Cummins12V98]

If you don't believe what I am writing call GY Tech Support!

If you are running the load range tire your RV came with run what they say for pressure. Most always MAX PSI.

With me so far?

Now if you up size as in load range like E to G tire then you should weigh your tires then look at the load/inflation guide for the upgraded tire. GY says to add 5psi to the recommended pressure.

I had GY E Wrangler LT tires stock on my Avion Platinum. I was near the weight limit, never had a problem but wanted more load capacity. I went with GY G tires and low and behold the inflation chart said I should run 80psi. I ran 85 psi for 5 years never a single problem and many thousands of miles. At 5 years I removed the tires and put on Hankook E's for the trade inn and sold the GY G's on CL. The tires had perfectly even tread wear.

GY says to stick with what the RV Mfg says but if up sizing use the charts!

[Me_Again]

rhagfo wrote:

MM49 wrote:

Me Again wrote:
Max sidewall inflation seems to be a band aid that the ST tire people came up with in an attempt to increase the life cycle of their product, with mixed results and far as I can tell.

I have talked to Michelin several times and they state over inflation leads to impact damage to the tire and decrease contact/braking performance.

Chris

Wow, is there no limit to your dishonesty?
MM49

That is a true statement, where is the dishonesty. Had a neighbor that was a log truck owner, ran his tires at 90 psi (110 psi tires) to limit cuts and carcass damage from the large rocks used in logging roads.

Yes Russ I love it when people with light weight bumper pulls know more about tire problems on 5th wheels than people that actually own one and that have repeatly travel in the hot SW weather for many years.

Let's take several identical trailers with 6k alxes and the same type, model and year tow vehicle. Tires on trailer as follows:

1. Michelin XPS RIBs
2. Bridgestone Duravis R250s
3. Maxxis M8008STs
4. Carlisle Radial Trail RHs
5. Goodyear Marathons
6. Powering TowMax
7. Westlake Super STs
8. Firestone Transforce HT

Hit the road as a caravan and keep going until last man standing. Each day a switch is made between drivers, TV's and trailers. Mileage details are documented to determine if a given tire gets better mileage. Records are kept about inflation adjustments required. Tire wear readings are taken every 3000 miles.

Trailer Life will publish the findings! Marcus are you on board?

I am sure that Tredit and Tireco will want to front the cost of such a test!

Chris

[rhagfo]

MM49 wrote:

Me Again wrote:
Max sidewall inflation seems to be a band aid that the ST tire people came up with in an attempt to increase the life cycle of their product, with mixed results and far as I can tell.

I have talked to Michelin several times and they state over inflation leads to impact damage to the tire and decrease contact/braking performance.

Chris

Wow, is there no limit to your dishonesty?
MM49

That is a true statement, where is the dishonesty. Had a neighbor that was a log truck owner, ran his tires at 90 psi (110 psi tires) to limit cuts and carcass damage from the large rocks used in logging roads.

[garysol]

Wayne from Sailun got back to me pretty quick. I have not weighed my trailer yet (I will) but using a hypothetical max weight of 3,100lbs per tire (15,500GVWR/20% pin...etc...) Sailun suggested to maybe try 105psi to help soften the ride but not less than that. I am not sure that 105psi vs 110psi will make enough difference in ride and contact area to be worth reducing the weight carrying capacity. Wayne also brought up the point that with our big 5th wheels we many factors that will load and unload the tires as we travel such as wind, rough roads and uneven weight distribution.

[MM49]

Me Again wrote:
Max sidewall inflation seems to be a band aid that the ST tire people came up with in an attempt to increase the life cycle of their product, with mixed results and far as I can tell.

I have talked to Michelin several times and they state over inflation leads to impact damage to the tire and decrease contact/braking performance.

Chris

Wow, is there no limit to your dishonesty?
MM49

[garysol]

downtheroad wrote:

garysol wrote:
Not to beat a dead horse but I am a little confused after reading many threads on the subject.

Well, there you go now. I'm sure these replies have certainly cleared up you confusion.....:h

If you want a consensus, straight forward and absolutely correct answer to anything, just come to the RV Forum....:)

Well I decided to go straight to the source and have emailed Sailun directly for there thoughts on the subject. Sailun has no online inflation chart so if they send me one I will post it here for others.

[downtheroad]

garysol wrote:
Not to beat a dead horse but I am a little confused after reading many threads on the subject.

Well, there you go now. I'm sure these replies have certainly cleared up you confusion.....:h

If you want a consensus, straight forward and absolutely correct answer to anything, just come to the RV Forum....:)