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-   -   Endurance Tire pressure on 27FB Int'l (http://www.airforums.com/forums/f438/endurance-tire-pressure-on-27fb-intl-193226.html)

LAWBC 03-14-2019 10:08 PM

Endurance Tire pressure on 27FB Int'l
 
Just replaced original tires on my 27 FB International and set pressure at 70 PSI . I have read where some run lower pressure, my Marathons where 65 PSI and never had a problem with them for 6 years.



The installer tells me that the Endurance are 10 ply where the Marathons where only 6ply.


What tire pressure at cold do you set yours ?

wulfraat 03-14-2019 10:22 PM

Endurance Tire pressure on 27FB Int'l
 
I run my endurance at 65 on my 30 ... it weighs in at about 7,000 lbs across both axles hitched and ready for camping.

Here is the load chart for the endurance....

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

Technically @1,750lbs load per tire (hitched) 40lbs is acceptable assuming the front axle has 10% more load due to the trailers overall weight distribution. These tires are speed rated to 87mph.

I may drop down to 50-55;this season to improve ride quality whilst still being far north of minimum inflation requirement.

ROBERT CROSS 03-15-2019 05:28 AM

I run ours at 70, when hot they get to 73+- a psi or two.
TPMS will alarm at 65. Trailer 7640lb with wd set.
POI...I use 1000lb wd bars with 1200lb tongue weight, proper weight distribution helps soften the ride...SFSG

Bob
🇺🇸

crispyboy 03-15-2019 07:39 AM

Endurance "E" rated - target is 60 psi. Tires run cool with minimal increase in air pressure when warmed up.

Mollysdad 03-15-2019 08:03 AM

This will turn into "I know best".

The real answer is no one knows because trailer tires don't have a sticker like cars do.
(IMO, the Goodyear chart will drive you crazy)
I chose 65psi and I'm happy. On the road it goes up to 72 or so and it seems to ride well.

ROBERT CROSS 03-15-2019 08:33 AM

I guess we will just have to accept the fact that everyone has their own "target".😂

Bob
🇺🇸

out of sight 03-15-2019 08:34 AM

Quote:

Originally Posted by Mollysdad (Post 2220310)
This will turn into "I know best".

The real answer is no one knows because trailer tires don't have a sticker like cars do.
(IMO, the Goodyear chart will drive you crazy)
I chose 65psi and I'm happy. On the road it goes up to 72 or so and it seems to ride well.

My new 28 has a tire and load sticker. It calls for 80 PSI.

AlanMcD 03-15-2019 08:56 AM

The label on my Airstream says 80 PSI, I have it set to 75. Just had it to the factory and the Service Tech set the pressure.

jadatis 03-15-2019 09:17 AM

Most Endurance tires are yust like the old ST , calculated in maximum load for 65mph.
This allows more deflection then LT-tire of same sise and loadrange would need for the 99mph , the maxload is calculated for.
That is the reason why the old ST failed often.
The deflection was to the edges of safety, so a little more speed then 65mph, or litle more weight on tire, or little less pressure, and the tires overheated.

The old ST had better be given the same deflection as LT , so more reserve.
This means that if 65 psi for D-load old ST was given, you better use higher , but not allowed anymore, in earlyer days 10 psi above that was allowed.

Now the new Endurance also to much deflection , and also calculated to the edges of safety, and need higher pressure then the old because stiffer tire gives lesser surface on ground at same deflection.

All together, if you would let me calculate for the new, after giving me 100% accurate data( haha forget it) , it will probably come to that 80 psi, with maximum reserve, and still no bumping.

So dont think that with chanching to Endurance, you are safe with same pressures or even a bit higher, probably you better use max allowed of 80 psi for E-load.

rhpeahl 03-15-2019 10:18 AM

Tire pressure
 
We ran our Goodyears at 65psi for a year, then lowered the pressure to 52, still above the Goodyear recommendation for our FC27FBT.

The interior cushions are much less playful now, which tells us the ride is better for the trailer.

wulfraat 03-15-2019 10:58 AM

Quote:

Originally Posted by jadatis (Post 2220328)
Most Endurance tires are yust like the old ST , calculated in maximum load for 65mph.
This allows more deflection then LT-tire of same sise and loadrange would need for the 99mph , the maxload is calculated for.
That is the reason why the old ST failed often.
The deflection was to the edges of safety, so a little more speed then 65mph, or litle more weight on tire, or little less pressure, and the tires overheated.

The old ST had better be given the same deflection as LT , so more reserve.
This means that if 65 psi for D-load old ST was given, you better use higher , but not allowed anymore, in earlyer days 10 psi above that was allowed.

Now the new Endurance also to much deflection , and also calculated to the edges of safety, and need higher pressure then the old because stiffer tire gives lesser surface on ground at same deflection.

All together, if you would let me calculate for the new, after giving me 100% accurate data( haha forget it) , it will probably come to that 80 psi, with maximum reserve, and still no bumping.

So dont think that with chanching to Endurance, you are safe with same pressures or even a bit higher, probably you better use max allowed of 80 psi for E-load.

Goodyear published their load chart and speed rating for the new endurance tire. I have attached above.

Airstream use the 225/75R15 size endurance tire on 25'+ trailers.

The Endurance tire is speed rated to 87mph (not 65mph) based on the minimum inflation PSI, which is in turn based on the load on the tire. That is what Goodyear publish for this tire (no mystery on tire specs here :).

If you want to know what minimum PSI your specific trailer needs to adhere manufacture specifications, just run your trailer over the cat scale, calculate your tire load (per tire), and look up the minimum inflation requirement in the table based on the tire size.

If you want to go with a higher PSI than what is in the load chart there is no harm in doing so, you simply yield a firmer than necessary ride.

wulfraat 03-15-2019 11:01 AM

Quote:

Originally Posted by AlanMcD (Post 2220320)
The label on my Airstream says 80 PSI, I have it set to 75. Just had it to the factory and the Service Tech set the pressure.

Airstream have to put that number on your trailer for legal liability reasons (maximum inflation PSI). If you adhere to that number it will ensure that you cannot make a claim against airstream for damage / accident / injury / etc.. caused by an under-inflated tire for the load it carried.

Maximum inflation PSI is not the same as manufacturer recommended PSI for your particular application / trailer.

Manufacture (Goodyear in this case) actually determines the minimum inflation based on tire load. Chart above details this.

ROBERT CROSS 03-15-2019 11:29 AM

Do I really worry about riding in the AS?
I have never had any damage to the AS caused by excess tire pressure...bad axles, yep... overrated WD bars, yep... wheel balance, yep.

Disclaimer...I do not run at the sidewall max, but well over the 'load' chart #. A dual axle trailer has too much tire shear when turning to support the lower numbers...but as in all things AS....TETO.:wally:
Bob
🇺🇸

ElliotA 03-15-2019 12:07 PM

Endurance Tires on 28' S/O
 
I installed Endurance tires on my 2006 28' S/O last year and Discount Tire remmended 80# pressure which I found to be too much as all the cabinet doors in my trailer were popping open. I reduced the pressure to 70# cold and that fixed the problem.


My trailer has a GVWR of 9100# with a tongue weight of 1100# so I was concerned, but based on the tire temperature after long 70 mph hauls, everything appears to be just fine.


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