Goodyear Endurance Tire Load Ratings

[jgriffin7]

This past weekend I put 4 new Goodyear Endurance ST225/75R15 load range E tires on my travel trailer. The tires only need to support 2,000# each. But these new tires can support 2,830# at their max inflation of 80 psi. The tire shop went ahead and inflated them to 80 psi. Of course, I will not overload my 4,000# axles. But should I lower the inflation on the tires to better match the 2,000# load per tire? And if so, how do I find out load supported for various inflation amounts? Or do I just go about dumb, fat and happy, leave the tires at 80psi, and adhere to my axle limitations?

[fonzie]

Read this thread...

https://www.forestriverforums.com/fo...re-215204.html

[jgriffin7]

Thanks fonzie!! Holy poop! So I can run my new tires at the original 50 psi on my old tires and be just fine. My mind is blown.

[eye95]

Here is a link to the load/inflation charts for the tires you named.

There may be an updated chart. You may wish to search for it.

Based on that chart you need at least 45 psi. Some will recommend running at the max. That would be a huge difference over what you need. A greater psi means fewer si on the ground for the p on the tire.

You pays your money, and you takes your choice.

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

[lbrjet]

65 is plenty, but most people will tell you 80. I ran 65 in mine for over 18,000 miles till they were replaced due to age. Make sure your rim will support 80 if that is what you choose.

[jgriffin7]

Originally Posted by lbrjet

65 is plenty, but most people will tell you 80. I ran 65 in mine for over 18,000 miles till they were replaced due to age. Make sure your rim will support 80 if that is what you choose.

Well lbrjet, you've put a new thought in my brain that wasn't there before. How do I know what my rims support?

[MR.M]

Originally Posted by jgriffin7

This past weekend I put 4 new Goodyear Endurance ST225/75R15 load range E tires on my travel trailer. The tires only need to support 2,000# each. But these new tires can support 2,830# at their max inflation of 80 psi. The tire shop went ahead and inflated them to 80 psi. Of course, I will not overload my 4,000# axles. But should I lower the inflation on the tires to better match the 2,000# load per tire? And if so, how do I find out load supported for various inflation amounts? Or do I just go about dumb, fat and happy, leave the tires at 80psi, and adhere to my axle limitations?

How do you know you only have 2,000# per tire ? you may have one at 1800 one at 1900 one at 2300 etc . nothing wrong with running max psi and have a good amount of cushion . the only reason to go down in psi would be abnormal tire wear in the center .

[MR.M]

Originally Posted by jgriffin7

Well lbrjet, you've put a new thought in my brain that wasn't there before. How do I know what my rims support?

Psi is relative to weight . has nothing to do with if a rim can handle 65 psi or 80 psi . the psi corresponds to a weight rating on a tire . if the rim say 2850 it can handle 80 if it say max 65 psi then it can handle the weight rating of a lrd 65 psi tire or 2450 etc

[jgriffin7]

Originally Posted by MR.M

How do you know you only have 2,000# per tire ? you may have one at 1800 one at 1900 one at 2300 etc . nothing wrong with running max psi and have a good amount of cushion . the only reason to go down in psi would be abnormal tire wear in the center .

Because I spent a lot of time at the CAT scales measuring every tire. None were higher than 1,850#, but because my axles are rated at 4,000#, I know that 2,000# is the average weight per tire to support the axle. Also, that was the max weight printed on each original tire. I only asked my original question because the Goodyear Endurance far exceed what was originally on my trailer.

[llr]

I run mine a little over the chart pressure (3-5psi) for a larger margin, no reason to run at 80. You will have a harsher ride with no benefit.
I know a lot of people say run at max and for the factory tires that is probably true most of the time. If the factory really thought max was best the tires would say run at X instead of maximum X and they would not publish the load inflation charts.

[Airdale]

Originally Posted by jgriffin7

This past weekend I put 4 new Goodyear Endurance ST225/75R15 load range E tires on my travel trailer. The tires only need to support 2,000# each. But these new tires can support 2,830# at their max inflation of 80 psi. The tire shop went ahead and inflated them to 80 psi. Of course, I will not overload my 4,000# axles. But should I lower the inflation on the tires to better match the 2,000# load per tire? And if so, how do I find out load supported for various inflation amounts? Or do I just go about dumb, fat and happy, leave the tires at 80psi, and adhere to my axle limitations?

You didn't provide enough information for anyone to make a valid recommendation. We would need the designated size of the Original Equipment tire and their load range letter. Also the GAWR numbers from the vehicle certification label.

[jgriffin7]

Originally Posted by Airdale

You didn't provide enough information for anyone to make a valid recommendation. We would need the designated size of the Original Equipment tire and their load range letter. Also the GAWR numbers from the vehicle certification label.

I appreciate your feedback. Sorry, I thought I had mentioned that the axles were 4,000# rated. And the original tires were C rated; same dimensions as what I used for the replacement.

[Airdale]

Originally Posted by jgriffin7

I appreciate your feedback. Sorry, I thought I had mentioned that the axles were 4,000# rated. And the original tires were C rated; same dimensions as what I used for the replacement.

Because your new tires are the same designated size as the originals, the placard pressure for them is still valid. Your options are to use inflation pressures from 50 PSI to 80 PSI.

At 2150# your OE tires were not providing much load capacity reserves. Because you've gone all the way to a LRE you should use an inflation pressure that will provide at lease 20% more than 4000# (somewhere between 60 - 65 PSI). I've provided a load inflation chart in the reference.

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

[babock]

Originally Posted by Airdale

Because your new tires are the same designated size as the originals, the placard pressure for them is still valid. Your options are to use inflation pressures from 50 PSI to 80 PSI.

At 2150# your OE tires were not providing much load capacity reserves. Because you've gone all the way to a LRE you should use an inflation pressure that will provide at lease 20% more than 4000# (somewhere between 60 - 65 PSI). I've provided a load inflation chart in the reference.

https://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

X2

[SailorSam20500]

My thoughts on tires for multi-axle travel trailers.

1. Your tires will age out long before the tread is gone unless there is something significantly wrong.
2. I think the maximum life on tires for this application is 5 years.
3. I believe turns place a lot of stress on tires in this application, to the extent that people have reported popping tires off the wheel when making a tight turn.
4. I think the major issue for tires is inter-ply shear. Lots of info available on the web on this. The link provided by Fonzie has a link to Roger Marble"s (tire engineer) recommendation and that has links to other articles by Roger.
5. Lower PSI than max may provide a softer ride for the trailer.
6. Max PSI may cause faster wear on tire center, I think the tire will age out before this is an issue.

It's up to you to decide. In other applications, using the tire charts to run at 20-25% more capacity than your actual load seems to be prudent.

[dalford]

Originally Posted by jgriffin7

Because I spent a lot of time at the CAT scales measuring every tire. None were higher than 1,850#, but because my axles are rated at 4,000#, I know that 2,000# is the average weight per tire to support the axle. Also, that was the max weight printed on each original tire. I only asked my original question because the Goodyear Endurance far exceed what was originally on my trailer.

I’m interested in your process of measuring the weight of every tire at the CAT scales. I’ve often wondered what the weight distribution is on each of my tires.

I know there are places that do that but I don’t know of one near me. A CAT scale is nearby.

[babock]

Originally Posted by SailorSam20500

I think the major issue for tires is inter-ply shear. Lots of info available on the web on this.

Out of curiosity, you have any web links that describe interply shear problems that are not authored by Roger? I have looked and have not seen "Lots of info available on the web on this". Specifically, it would be nice to hear it from the tire manufacturers themselves.

[lbrjet]

My rims are stamped max 2,540lbs so I interpreted that to mean 65 psi max. Others say you can put any psi in any rim. Doesn't make sense to me so I went with what was logical to me and it worked out fine.

[CedarCreekWoody]

I recently upgraded to the same tire, 80 psi. However I run only 65 psi, the amount recommended for my trailer and by the weight chart.

[SailorSam20500]

Originally Posted by babock

Out of curiosity, you have any web links that describe interply shear problems that are not authored by Roger? I have looked and have not seen "Lots of info available on the web on this". Specifically, it would be nice to hear it from the tire manufacturers themselves.

Ask and ye shall receive. Take some aspirin before reading... https://etda.libraries.psu.edu/files...bmissions/3206


https://meridian.allenpress.com/rct/...dFrom=fulltext


https://tiresciencetechnology.org/do...2346/1.2999704


The last 2 are not free unless you belong to the correct groups.


And you have watched the u-tube showing the slide load that is the basis for inter-ply shear. Obviously the load is even greater when making a tight turn backing into a camping spot.

https://youtu.be/8jx8xr7aQto


Roger has published a lot on this topic.