What should the PSI be in the trailer?

[rbp111]

I have a trailer which has Sailun G rated tires. The maximum PSI of air is listed as 110 PSI. I was carrying 90 PSI but recently was told that the maximum PSI, that is 110 PSI is the amount of air I need to carry.
Which is the amount I should have in the tires?

[Cummins12V98]

Lantley wrote:
The issue with all this dialing in and weighing is that it does not give you any added margin. I don't want my tires to be exactly at their capacity. I want a bit of additional capacity or safety margin.
When I hit a run of pot holes and rough roads I want my tires to be able to withstand the additional impact.
My G rated Sailun's are up to the challenge. Aired to 110 PSI I have lots of margin to withstand the rough roads. MY E rated OEM tires were not up to the challenge and I ended up with blowouts forcing me to seek a better tire.
G rated Sailun's aired up to 110 have resolved all my tire issues.
No charts or individual wheel weights required.
I had the same issue with my prior RV. The D rated tires were not up to the challenge, but E rated tires aired to the max resolved my blowouts issues once again.
In the end you can weigh and air to match some mystical chart if you like but I will go with the max. PSI method.
I am referring to RV trailers only. Most other trailers have totally different characteristics and aerodynamics, the max. pressure method may not apply

Do you run your 4 rear truck tires at their MAX 80psi?

Bottom line RUN QUALITY TIRES!

I have never had a flat or blowout on a RVtire EVER.

[CALandLIN]

fj12ryder wrote:

CALandLIN wrote:

fj12ryder wrote:
Actually Keystone "derated" the axles to get the tires to meet the tire/axle rating. They are 7,000 lb. rated axles, according to Dexter when I checked with them, but Keystone "derated" them to 6,800 lbs. so the "E" rated tires, at 3,400 lbs. each, would work.

How's that for working with the numbers. And a CYA.

Keystone and a lot of other RV trailer manufacturers got into a "catch 22" with those 7000# axle certifications. The easiest way for them to remedy it (IMO) was to deduct a couple of hundred pounds off the trailer's cargo capacity and derate the axles which they are allowed to do. The culprit is the ST235/80R16E tires. Different tire manufacturers have used different load capacities for that identical sized tire. 3420# and 3520#, both at 80 PSI MAX. The 3420# tire does not qualify for use as OEM on 7000# certified axles.


Reason: Elsewhere in the FMVSS there is a standard that says when two identical tires have different maximum load capacities they automatically default to the lower rating.

It's not really a "Catch 22", all they had to do was put tires on that would meet the axle specs. Which now is getting to be very common. You see quite a few "G" rated LT/ST tires on larger 5th wheels.

But rather than go to the expense of putting real tires on these heavy, tall trailers, they put on flimsy "E" rated ST tires and "derate" the axles so they can get away with it. What a racket.

The "catch 22" was; consumers already had the trailers. Look at it from the trailer manufacturer's point of view. Lower the cargo capacity and put on new certification labels with adjusted GAWRs or recall all mislabeled trailers and put on new tires.

[Lantley]

The issue with all this dialing in and weighing is that it does not give you any added margin. I don't want my tires to be exactly at their capacity. I want a bit of additional capacity or safety margin.
When I hit a run of pot holes and rough roads I want my tires to be able to withstand the additional impact.
My G rated Sailun's are up to the challenge. Aired to 110 PSI I have lots of margin to withstand the rough roads. MY E rated OEM tires were not up to the challenge and I ended up with blowouts forcing me to seek a better tire.
G rated Sailun's aired up to 110 have resolved all my tire issues.
No charts or individual wheel weights required.
I had the same issue with my prior RV. The D rated tires were not up to the challenge, but E rated tires aired to the max resolved my blowouts issues once again.
In the end you can weigh and air to match some mystical chart if you like but I will go with the max. PSI method.
I am referring to RV trailers only. Most other trailers have totally different characteristics and aerodynamics, the max. pressure method may not apply

[CALandLIN]

Cummins12V98 wrote:

CALandLIN wrote:

Cummins12V98 wrote:
Give GY Tech a call and ask them what to do when going from a "E" to "G" tire. They will tell you to use the chart and add 5psi.

Why do you think they make the chart? MOST RV's axle rating is determined buy the tires capacity at MAX psi.

Using that method on the LT235/85R16E to a LRG would increase the load capacity from 3042# to 3170#.


The same method for a ST235/85R16E to LRG would increase the load capacity from 3640# to 3750#.


As you can see, load inflation charts are not compatible between tire size designations.

Not sure your point as it relates to what I said.

Just pointing out that each designated tire size has its own standardized load inflation chart.


LT235/85R16 is a designated tire size. ST235/85R16 is a designated tire size. A tire's load rating, weather it be from its load index number or load range leter is a condition of the tire and not rerlated to its size.

[fj12ryder]

CALandLIN wrote:

fj12ryder wrote:
Actually Keystone "derated" the axles to get the tires to meet the tire/axle rating. They are 7,000 lb. rated axles, according to Dexter when I checked with them, but Keystone "derated" them to 6,800 lbs. so the "E" rated tires, at 3,400 lbs. each, would work.

How's that for working with the numbers. And a CYA.

Keystone and a lot of other RV trailer manufacturers got into a "catch 22" with those 7000# axle certifications. The easiest way for them to remedy it (IMO) was to deduct a couple of hundred pounds off the trailer's cargo capacity and derate the axles which they are allowed to do. The culprit is the ST235/80R16E tires. Different tire manufacturers have used different load capacities for that identical sized tire. 3420# and 3520#, both at 80 PSI MAX. The 3420# tire does not qualify for use as OEM on 7000# certified axles.


Reason: Elsewhere in the FMVSS there is a standard that says when two identical tires have different maximum load capacities they automatically default to the lower rating.

It's not really a "Catch 22", all they had to do was put tires on that would meet the axle specs. Which now is getting to be very common. You see quite a few "G" rated LT/ST tires on larger 5th wheels.

But rather than go to the expense of putting real tires on these heavy, tall trailers, they put on flimsy "E" rated ST tires and "derate" the axles so they can get away with it. What a racket.

[CALandLIN]

fj12ryder wrote:
Actually Keystone "derated" the axles to get the tires to meet the tire/axle rating. They are 7,000 lb. rated axles, according to Dexter when I checked with them, but Keystone "derated" them to 6,800 lbs. so the "E" rated tires, at 3,400 lbs. each, would work.

How's that for working with the numbers. And a CYA.

Keystone and a lot of other RV trailer manufacturers got into a "catch 22" with those 7000# axle certifications. The easiest way for them to remedy it (IMO) was to deduct a couple of hundred pounds off the trailer's cargo capacity and derate the axles which they are allowed to do. The culprit is the ST235/80R16E tires. Different tire manufacturers have used different load capacities for that identical sized tire. 3420# and 3520#, both at 80 PSI MAX. The 3420# tire does not qualify for use as OEM on 7000# certified axles.


Reason: Elsewhere in the FMVSS there is a standard that says when two identical tires have different maximum load capacities they automatically default to the lower rating.

[Cummins12V98]

CALandLIN wrote:

Cummins12V98 wrote:
Give GY Tech a call and ask them what to do when going from a "E" to "G" tire. They will tell you to use the chart and add 5psi.

Why do you think they make the chart? MOST RV's axle rating is determined buy the tires capacity at MAX psi.

Using that method on the LT235/85R16E to a LRG would increase the load capacity from 3042# to 3170#.


The same method for a ST235/85R16E to LRG would increase the load capacity from 3640# to 3750#.


As you can see, load inflation charts are not compatible between tire size designations.

Not sure your point as it relates to what I said.

[CALandLIN]

Cummins12V98 wrote:
Give GY Tech a call and ask them what to do when going from a "E" to "G" tire. They will tell you to use the chart and add 5psi.

Why do you think they make the chart? MOST RV's axle rating is determined buy the tires capacity at MAX psi.

Using that method on the LT235/85R16E to a LRG would increase the load capacity from 3042# to 3170#.


The same method for a ST235/85R16E to LRG would increase the load capacity from 3640# to 3750#.


As you can see, load inflation charts are not compatible between tire size designations.

[fj12ryder]

Cummins12V98 wrote:
Max pressure may be CYA, but I CYA'ed the heck out of the lousy "E" rated ST tires that came on my trailer"

Most likely the tires had to be inflated to MAX to get the axle rating.

Actually Keystone "derated" the axles to get the tires to meet the tire/axle rating. They are 7,000 lb. rated axles, according to Dexter when I checked with them, but Keystone "derated" them to 6,800 lbs. so the "E" rated tires, at 3,400 lbs. each, would work.

How's that for working with the numbers. And a CYA.

[Cummins12V98]

Max pressure may be CYA, but I CYA'ed the heck out of the lousy "E" rated ST tires that came on my trailer"

Most likely the tires had to be inflated to MAX to get the axle rating.

[time2roll]

deleted

[fj12ryder]

Lantley wrote:

Cummins12V98 wrote:

fj12ryder wrote:

time2roll wrote:
The oem tires call for 110... I would be running 110 minimum.

Why? If you're getting good wear patterns and no issues with running lower pressures why would you blindly follow recommendations that are based on "E" rated ST tires? "G" rated LT/ST tires don't show the "B-Ball" effect, their sidewalls are too stiff for that to happen. There's quite a bit of data that suggests there's no reason to blindly follow the "Use Maximum Pressure" suggestions. Good wear patterns, long life, not beating your trailer to death, all good reasons to run lower pressures on "G" rated tires.

JMO of course, and I will continue to recommend that people with "G" rated tires experiment with air pressure until they find what works best for them.

Hey there is the BLIND way to go thru life using the CYA method or one can actually use their BRAIN and do what is BEST for their situation. I prefer the latter. 😉

Max pressure is CYA. I use the CYA method because I have suffered through the blowouts from the era when I did not use the max. Pressure CYA method.
Again I do not want to derate the tire by not filling it to max. PSI.

BY the way are you filling each tire to a different pressure using those charts? Are you assuming each wheel weighs the same and carries the same/equal load?

I have weighed each wheel so I know what they weigh. And I inflate my tires so the pressure is enough to carry the heaviest loaded tire. It doesn't have to be difficult if you actually stop and think it through.

Max pressure may be CYA, but I CYA'ed the heck out of the lousy "E" rated ST tires that came on my trailer, and I still had two of them fail.

As far as "derating" the tire, I don't need 4,000 lbs. of carrying capacity, so why use that air pressure? Does your empty truck have a very rough ride when you inflate your tires to max, or do you lower the air pressure when empty for a smoother ride? Why would you "derate" your tires like that? Or does that actually make sense? I run lower pressures on my 1-ton dually when it's empty because it rides like a lumber wagon if I don't. I don't consider that an issue. Should I be concerned that I've "derated" my tires?

My truck placard calls for about 50 psi in my front tires even though they are "E" rated LT tires and have a max of 80 psi. Should I be concerned that the manufacturer recommends I "derate" my tires?

On Edit, corrected the pressure to 80 psi from an incorrect 85 psi.

[fj12ryder]

Lantley wrote:

Cummins12V98 wrote:

fj12ryder wrote:

time2roll wrote:
The oem tires call for 110... I would be running 110 minimum.

Why? If you're getting good wear patterns and no issues with running lower pressures why would you blindly follow recommendations that are based on "E" rated ST tires? "G" rated LT/ST tires don't show the "B-Ball" effect, their sidewalls are too stiff for that to happen. There's quite a bit of data that suggests there's no reason to blindly follow the "Use Maximum Pressure" suggestions. Good wear patterns, long life, not beating your trailer to death, all good reasons to run lower pressures on "G" rated tires.

JMO of course, and I will continue to recommend that people with "G" rated tires experiment with air pressure until they find what works best for them.

Hey there is the BLIND way to go thru life using the CYA method or one can actually use their BRAIN and do what is BEST for their situation. I prefer the latter. 😉

Max pressure is CYA. I use the CYA method because I have suffered through the blowouts from the era when I did not use the max. Pressure CYA method.
Again I do not want to derate the tire by not filling it to max. PSI.

BY the way are you filling each tire to a different pressure using those charts? Are you assuming each wheel weighs the same and carries the same/equal load?

I have weighed each wheel so I know what they weigh. And I inflate my tires so the pressure is enough to carry the heaviest loaded tire. It doesn't have to be difficult if you actually stop and think it through.

Max pressure may be CYA, but I CYA'ed the heck out of the lousy "E" rated ST tires that came on my trailer, and I still had two of them fail.

As far as "derating" the tire, I don't need 4,000 lbs. of carrying capacity, so why use that air pressure? Does your empty truck have a very rough ride when you inflate your tires to max, or do you lower the air pressure when empty for a smoother ride? Why would you "derate" your tires like that? Or does that actually make sense? I run lower pressures on my 1-ton dually when it's empty because it rides like a lumber wagon if I don't. I don't consider that an issue. Should I be concerned that I've "derated" my tires?

My truck placard calls for about 50 psi in my front tires even though they are "E" rated LT tires and have a max of 85 psi. Should I be concerned that the manufacturer recommends I "derate" my tires?

[fj12ryder]

time2roll wrote:

fj12ryder wrote:

time2roll wrote:
The oem tires call for 110... I would be running 110 minimum.

Why?

Because the engineers that put the sticker on the trailer decided to put "110" in the box for inflation pressure.

Do you weigh your vehicle to use less pressure than the door sticker on all your vehicles?

You can do as you please. I simply stated what I would do.

As a matter of fact I did weigh each wheel so I would know what weight I'm carrying and know that I'm not going to overload my tires.

[Cummins12V98]

Lantley wrote:

Cummins12V98 wrote:

fj12ryder wrote:

time2roll wrote:
The oem tires call for 110... I would be running 110 minimum.

Why? If you're getting good wear patterns and no issues with running lower pressures why would you blindly follow recommendations that are based on "E" rated ST tires? "G" rated LT/ST tires don't show the "B-Ball" effect, their sidewalls are too stiff for that to happen. There's quite a bit of data that suggests there's no reason to blindly follow the "Use Maximum Pressure" suggestions. Good wear patterns, long life, not beating your trailer to death, all good reasons to run lower pressures on "G" rated tires.

JMO of course, and I will continue to recommend that people with "G" rated tires experiment with air pressure until they find what works best for them.

Hey there is the BLIND way to go thru life using the CYA method or one can actually use their BRAIN and do what is BEST for their situation. I prefer the latter. 😉

Max pressure is CYA. I use the CYA method because I have suffered through the blowouts from the era when I did not use the max. Pressure CYA method.
Again I do not want to derate the tire by not filling it to max. PSI.

BY the way are you filling each tire to a different pressure using those charts? Are you assuming each wheel weighs the same and carries the same/equal load?

You are supposed to weigh each tire if possible and air that axle to the highest weight.

I run MAX on my DRV because I have a HUGE axle load. I run my ENDURANCE tires based on load on my Boat trailer. I run my MAXXIS tires based on load on my MC trailer (ENDURANCE were not available). If I were to run MAX the MC trailer would be bouncing down the road. I inferred all 12 of my tires at every stop and in ALL conditions they are running cool.

Should I rum my DRW's rear tires at 80??? Do you ???

My truck placard says 65 for full load, I run full RAWR so I run 65 as the weight/inflation chart will also tell you.