Tire Pressure on Goodyear Endurance

[kbmwrs]

Ok we settled tire pressure....now Which TV and oil should I use?
I know all can be agreed upon.


Just kidding.

[Dr. Dean]

Goodyear tire air pressure. The Airstream factory specifically recommends to run the tires at 80 pounds psi. I run my trailer at 80 pounds and have very little to nowhere on the tires. The trailer does not get bounced around like everyone thinks.
Dr. Dean

[field & stream]

Originally Posted by Dr. Dean

Goodyear tire air pressure. The Airstream factory specifically recommends to run the tires at 80 pounds psi. I run my trailer at 80 pounds and have very little to nowhere on the tires. The trailer does not get bounced around like everyone thinks.
Dr. Dean

Not sure you are right that the “Airstream factory specifically recommends to run the tires at 80 pounds psi”. Can you provide a source for this?

One example: my trailer has a factory metal tag riveted to the body that says 50 psi, and my new Goodyear Endurance tires say 65 psi on the sidewalls. Another: A friend’s factory tag says 65 psi. Question: What does your tag say?

It is blanket statements like the above that keep people confused……

[dmcintee]

Originally Posted by Chazblank

Just got a set of Goodyear Endurance on our 25' Safari. What is a good tire pressure for these. I ran my old tires at max (50psi) and these are 80psi max and that seems excessive. Thanks, Charlie

We recently got a new set of trailer tires, and they were inflated to 80. I asked the manager at the tire store and he said 80 was his recommendation. I can’t quite bring myself to inflate that high, so I have been keeping them at about 65, which is more than I used to keep my old set. I watch the tire temperature with a TPMS for temps rising more than about 10 degrees over the air temperature. So far so good.

[jadatis]

Originally Posted by Llando88

So, more on the subject of "do I understand this correctly" and not "what pressure should I use", can I ask you guys to look over the attached chart?

I haven't been able to weigh my rig (2022 GT23FBT) yet, so I used the GVWR, figuring it should not be above that. I added a margin (15%) to that, then computed the "load" assuming equal distribution on each tire. I then looked up the load capacity (I think its the load capacity?) of the tires from the famous inflation chart.

Based on that, I calculated the percent load I am at, for each of the common pressures you see (80 psi down to 65 psi) folks cite they run their GYE on.

Does this make sense?

Calculatedcit with my made spreadsheet first for 65mph max, gave 43psi advice, and then for 6 loadindex steps lower to give highest pressure without rivets popping, gave 51 psi.

So , as I wrote in my first reaction on this post, in any case your Airstream tires have a comfortable reserve. Even C-load in this sise has enaugh loadcapacity.

In this the Airstream tandemaxle travel trailers are an exeption.

All this assuming you dont overload , and only weighing fully loaded is the way to be 100% certain of that.

But TT makers also determine recomended pressure on GVWR , mayby GAWR's.

I mean to remember tgat I once calculated for gypsydad
And came to 58 psi, wich was about what he used ( 55 to 60psi.).

So in general , if you go from C- to E- load on a tandemaxle Airstream, you need only a bit higher then 50 psi, and the C-load can do perfectly with the 50 psi.

In the forestriver topic , I mentioned that , what I expected , learned from the airstreams tandemaxles, that they had a comfotable reserve in tires, was not tru for the forestriver TT, needed 74 psi. And the AT 50 psi C-load 64 psi, so higher then reference of 50 psi.

[Tireman9]

Originally Posted by Mollysdad

The GoodYear chart is the same chart used for GY Marathons, so that should tell you something.
I always ask those using the chart to explain it. They can't.
So, instead of the recommended 28 psi, I decided on 65 psi.
"If driving on I-95 or I-10, reduce pressure to 60 psi." That's science, man!


Where did you find a suggestion that 28 psi would be correct?


Why would I understand that? The word minimum doesn't appear anywhere. Is Goodyear that careless?

When you look at the Load/Inflation chart you will see that to support 2148 # on a ST225/75R15 you need a pressure of at least 50 psi. If you need to support a greater load say 2375# you must run a higher pressure. In our example that would require 65 psi cold. So logically the pressure needed to support a given load XXX# is the pressure in the chart that is rated to support at least XXXX# So that is why it is called the MINIMUM inflation.

The pressure in the tables is the COLD inflation which means the inflation when measured when the tire has not been driven or in direct sunlight (ie warmed up) for the previous 2 hours. You can think of this as the Temperature "IN the Shade".

Also actual tire engineers (Capri and I) know that tires warm up and take that into consideration when we design, test and spec a tire.




Side issues You should not inflate a tire to a pressure that is higher than the wheel is rated for.
I and I am sure Capri would also, recommend the use of "bolt-in" metal valve stems in RV use. Especially when you use a TPMS which we both recommend.

[JimCT]

Originally Posted by ROBERT CROSS

Sounds WAY more complicated than it actually is.

I've found over the years that TP has very little to do with damage to our trailer.
I have pooped rivets, when our lash-up with 1400lb WD bars was much to stiff.

You would have to inflate the tire way over 150psi to cause it damage.
You are safe at the sidewall recommendation. TETO
Under inflation is the most common cause of catastrophic tire failure.

Bob
🇺🇦🇺🇸🇺🇦

The sidewall max pressure is the max pressure not at all a recommendation for an operating pressure. It is the max pressure used to set the bead when mounting the tires. Does anyone run their tow vehicle or family car with the tires at max pressure? I doubt that.

[Gene]

Just because Airstream recommends 80 psi does not mean they know what they are talking about. Same for some tire stores.

Popped rivets, drawers flying around, etc. are not necessarily caused by excess tire pressure. How you drive, road conditions, poor workmanship, cheap materials, type of hitch, all can contribute.

We used 62-64 psi with Michelin load range E tires on a 25FB Safari. It worked for us.

Check tread wear with a tread wear gauge. It can give you a clue if the tires wear unevenly that there is a problem. Overinflated tires wear most in the center treads. Overinflated tires also wear faster. Underinflated tires tend to wear more at the edges. A gauge can help you fine tune tire pressure for your particular rig.

[Action]

Originally Posted by JimCT

It is the max pressure used to set the bead when mounting the tires.

Would you post a reference for this opinion?

Filling tires to max side wall pressure could be needed if the load on the tires is great enough. That will not happen on cars because the tires used have way too
much capacity.

However not too long-ago trailer manufacturers used tires that were marginal at best as far as load capacity. It was a cost cutting measure. And these applications did not carry passengers so federal regulations were different. It was necessary to inflate those tires to max posted side wall to get the load capacity needed. And in some cases those tires were not up for the job.

Action

[jadatis]

Originally Posted by JimCT

The sidewall max pressure is the max pressure not at all a recommendation for an operating pressure. It is the max pressure used to set the bead when mounting the tires. Does anyone run their tow vehicle or family car with the tires at max pressure? I doubt that.

For setting the beads often a long story on sidewall , then lower then max pressure.

Max pressure of P-tires is higher then the referencepressure, and only given on P-tires.
On LT and trucktires mostly only referencepressure is given often after AT, but sometimes the confusing maxpress behind it.

Some Electric cars have maximum cold pressure recomended, for more actiradius of battery.
That comfort is bad , they dont care, all for good selling figures .
And centrewear only happens at much to high pressure. I estimate when lesser then 60% of loadcapacity belonging to the pressure is on tire.

Only saw 1 topic on Tesla forum , in wich centrewear was noticed.

[Justinfinity]

There is a very good post by ETroup about this often discussed topic in another thread:

https://www.airforums.com/forums/f43...ml#post2536934

Once you have done the calculation according to the Goodyear chart and ETroup's methodology, you still have to keep in mind:

(a) the cold inflation pressure;
(b) the climate in which you will be driving; and
(c) the variability from the cold inflation pressure to the stabilized "warm" tire pressure given the conditions you are driving in.

As a newbie, I was over-inflating because I read the chart and the tire info in an oversimplified way and basically inflated to the max.

When I gained more experience and had the real-time TPMS data, I realized I was over-inflating and backed off my cold inflation pressure to 65psi. On long drives in hot climates, the tire pressure rises to 75psi.

In cold climates, initially as I start out, I get low tire pressure warnings from the TPMS but then as the tires warm up, even, in the cold, everything stabilizes and the TPMS low-pressure warnings stop (yes, I could adjust the low pressure warning but i haven't because I'm more likely to tow in warm climate conditions).

Have a look at TRoup's post. It essentially settles the whole discussion.

[Dan and Liz]

Originally Posted by CapriRacer

No, tire pressure has been a hot topic since - well - forever. It's one of the few things people have a choice on. After all, you just can't change the size of the lugnuts!

This particular version is because the trailer manufacturers finally stepped up and realized the rest of the world - meaning car and truck manufacturers - were using good engineering principles and quit undersizing tires. We are now in the midst of that changeover repercussion.

Ya see, nowadays all the car and truck manufacturers produce vehicles with appropriately sized tires and inflation pressures - and that is reflected on the vehicle tire placard. Only occasionally does someone question the car or truck manufacturer's specification - usually pickup owners.

In an ideal world, trailer manufactures would have been just as diligent and people could follow the placard specification without questioning it.
Unfortunately we don't live in that world.

Capri Racer: My question is related to TV rather than trailer. Would you advise increasing rear tire pressure above vehicle placard when towing because of tongue/cargo weight? (Truck placard is 35 psi and max pressure on tire sidewall is 44 psi.)

[Hans627]

Originally Posted by Justinfinity

There is a very good post by ETroup about this often discussed topic in another thread:

https://www.airforums.com/forums/f43...ml#post2536934

Once you have done the calculation according to the Goodyear chart and ETroup's methodology, you still have to keep in mind:

(a) the cold inflation pressure;
(b) the climate in which you will be driving; and
(c) the variability from the cold inflation pressure to the stabilized "warm" tire pressure given the conditions you are driving in.

As a newbie, I was over-inflating because I read the chart and the tire info in an oversimplified way and basically inflated to the max.

When I gained more experience and had the real-time TPMS data, I realized I was over-inflating and backed off my cold inflation pressure to 65psi. On long drives in hot climates, the tire pressure rises to 75psi.

In cold climates, initially as I start out, I get low tire pressure warnings from the TPMS but then as the tires warm up, even, in the cold, everything stabilizes and the TPMS low-pressure warnings stop (yes, I could adjust the low pressure warning but i haven't because I'm more likely to tow in warm climate conditions).

Have a look at TRoup's post. It essentially settles the whole discussion.

I agree and this is exactly why I use 65 psi on my GT.

Thanks for posting this link!

[field & stream]

I agree: excellent link to an excellent post. Also an excellent joke: “It essentially settles the whole discussion“. LOL

[2012FB]

Even the tire shops don't understand and go by the max 80psi stated on the trailer placard. Frankly, Airstream should indicate the actual PSI required for a specific tire/trailer weight. I purchased new 16' SenDel wheels and Michelin XPS RIBs from Discount Tire. I got there early Saturday morning to have them swap out the 15" set. I told the young technician that I wanted 55psi put in the new tires. He walks out to the trailer, looks at the placard, and says he "has" to put 80psi in. Without explanation, I just politely asked to see the store manager. When the store manager came out we had a brief discussion that the 80psi was the manufactures maximum PSI tire rating and did not take into account the actual load on the tires. I had printed out the Michelin Inflation Charts for RV usage and we both reviewed the LT225/75R16 LRE XPS RIB, PSI to load rating and he agreed that 55psi cold would be more than enough pressure for the load.

[ROBERT CROSS]

Originally Posted by 2012FB

Even the tire shops don't understand and go by the max 80psi stated on the trailer placard. Frankly, Airstream should indicate the actual PSI required for a specific tire/trailer weight. I purchased new 16' SenDel wheels and Michelin XPS RIBs from Discount Tire. I got there early Saturday morning to have them swap out the 15" set. I told the young technician that I wanted 55psi put in the new tires. He walks out to the trailer, looks at the placard, and says he "has" to put 80psi in. Without explanation, I just politely asked to see the store manager. When the store manager came out we had a brief discussion that the 80psi was the manufactures maximum PSI tire rating and did not take into account the actual load on the tires. I had printed out the Michelin Inflation Charts for RV usage and we both reviewed the LT225/75R16 LRE XPS RIB, PSI to load rating and he agreed that 55psi cold would be more than enough pressure for the load.

YEP, they sure do...BSTS. The tires were deigned for running safely at sidewall pressure under ALL spec loads.

Bob
🇺🇦🇺🇸🇺🇦

[richard5933]

Originally Posted by 2012FB

Even the tire shops don't understand and go by the max 80psi stated on the trailer placard. Frankly, Airstream should indicate the actual PSI required for a specific tire/trailer weight. I purchased new 16' SenDel wheels and Michelin XPS RIBs from Discount Tire. I got there early Saturday morning to have them swap out the 15" set. I told the young technician that I wanted 55psi put in the new tires. He walks out to the trailer, looks at the placard, and says he "has" to put 80psi in. Without explanation, I just politely asked to see the store manager. When the store manager came out we had a brief discussion that the 80psi was the manufactures maximum PSI tire rating and did not take into account the actual load on the tires. I had printed out the Michelin Inflation Charts for RV usage and we both reviewed the LT225/75R16 LRE XPS RIB, PSI to load rating and he agreed that 55psi cold would be more than enough pressure for the load.

Tire shops are not going to weigh each vehicle they put tires on, and Airstream has no idea how heavily you'll load it up. The only safe option for them is to go by the max. If we want to adjust based on actual load, then we're all able to do so.

[2012FB]

Originally Posted by richard5933

Tire shops are not going to weigh each vehicle they put tires on, and Airstream has no idea how heavily you'll load it up. The only safe option for them is to go by the max. If we want to adjust based on actual load, then we're all able to do so.

No need to weigh it. Just need to be able to read the placard which states the GVWR, and the sidewall of the tire for identification. Then look it up on the tire manufacturers' inflation chart, in my case, Michelin Inflation Charts for RV Usage, and chose the correct air pressure for the specific tire and the load per tire. Very easy to do. This is why tire manufacturers publish inflation charts. But hey as pointed out 80psi works all day long for those who don't want to take the time or understand the proper inflation requirements for their specific trailer. I just love this site. Nothing gives me a bigger chuckle.

[gypsydad]

Originally Posted by richard5933

Tire shops are not going to weigh each vehicle they put tires on, and Airstream has no idea how heavily you'll load it up. The only safe option for them is to go by the max. If we want to adjust based on actual load, then we're all able to do so.

Are you sure about that?? That seems to me why there is so much "confusion" in this thread from everyone, right? I remember the example somewhere awhile back, of how you "don't" want to ride in a trailer being towed down the highway, due to harshness jostling around inside and of course safety issues (from jostling in back). Stands to reason you want the tires and suspension to be at a happy medium with some forgivness so as not to give such a stiff ride. Road conditions aside, makes perfect sense (to me at least) that running at "Max PSI" creates stiff "unforgiving" ride to the trailer and indeed causes the popped rivets, hinge/latch, etc issues. I don't know where some of these folks drive that run max psi without these issues are, but I want to live in that state! Like I mentioned, it's not "rocket science"...lower your PSI below max when cold, experiment if you must, listen to the experts, or just continue to be baffled because we all can't agree... Overall, agree with your last comment.

[richard5933]

Originally Posted by 2012FB

No need to weigh it. Just need to be able to read the placard which states the GVWR, and the sidewall of the tire for identification. Then look it up on the tire manufacturers' inflation chart, in my case, Michelin Inflation Charts for RV Usage, and chose the correct air pressure for the specific tire and the load per tire. Very easy to do. This is why tire manufacturers publish inflation charts. But hey as pointed out 80psi works all day long for those who don't want to take the time or understand the proper inflation requirements for their specific trailer. I just love this site. Nothing gives me a bigger chuckle.

This wouldn't tell you anything about the actual weight in the trailer, an if someone loaded it beyond the GVWR. They're going to always cover their back side.

My Subaru dealer does the same - they always fill the tires to the placard pressure, no matter how many times I've asked them to use a different number.