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Old 11-13-2020, 04:01 AM   #1
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Model: Challenger 37FH
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Tire PSI

Hello everyone,

I have a 2020 Challenger 37FH. The tire size is 255/80 R22.5 XRV. The rv weighs in at 7,890 lbs front axle, 15,990 lbs rear axle.

I was advised to fill my tires at 110 psi for all six tires.

Does this sound right?

Thanks in advance.
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Old 11-13-2020, 04:12 AM   #2
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What does the tire manufacturer recommend?
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Old 11-13-2020, 04:29 AM   #3
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[QUOTE=Lt Keefer;263871]What does the tire manufacturer

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I think, according to the chart, 110 psi. But it just seems really high to me.
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Old 11-13-2020, 04:31 AM   #4
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[QUOTE=Sdkim;263872]
Quote:
Originally Posted by Lt Keefer View Post
What does the tire manufacturer

Attachment 27123

I think, according to the chart, 110 psi. But it just seems really high to me.


Am I reading the chart correctly?
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Old 11-13-2020, 11:57 AM   #5
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110 seems high...
But this is not your family sedan.
Give it a try.
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Old 11-13-2020, 11:59 AM   #6
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What does it say on the inside of the driver side door?
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Old 11-13-2020, 12:46 PM   #7
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What does it say on the inside of the driver side door?
The yellow sticker... Not the one put there by Ford.
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Old 11-13-2020, 12:55 PM   #8
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Not the same chart so see which says about 75 front and 80 to 85 rear.

On my coach the Michelin recommendation is too low and cause too much side wall flex. Based on weight they say 75 which is down from 110. I set mine at 100 and it rides well. My tires are 285 XXE and not 255 XRV.

If I remember correctly the recommendation for our 2015 Challenger 37ND was 90 front and rear. Not positive on that.
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Old 11-13-2020, 01:39 PM   #9
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My 2019 Challenger 37fh fully loaded 100gals water 80gal fuel and everything else fo fulltime living, frt 8200# rear 16040# I run 100psi all around and 2 1/2yrs up and down east coast no problems coach handles very well. Check the Michelin rv tire chart I think it's 80 ft 85rear. Check the yellow sticker on bottom panel on inside of screen door.
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Old 11-13-2020, 02:52 PM   #10
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Quote:
Originally Posted by Sdkim View Post
Hello everyone,

I have a 2020 Challenger 37FH. The tire size is 255/80 R22.5 XRV. The rv weighs in at 7,890 lbs front axle, 15,990 lbs rear axle.

I was advised to fill my tires at 110 psi for all six tires.

Does this sound right?

Thanks in advance.
[QUOTE=Sdkim;263872]
Quote:
Originally Posted by Lt Keefer View Post
What does the tire manufacturer

Attachment 27123

I think, according to the chart, 110 psi. But it just seems really high to me.

OK, rough numbers from your axle weights are 4000 lbs per tire.
From your chart:
For singles (front) you can support 4070 lbs per tire at 75 PSI
For duals (rear) you can support 8080 lbs per pair at 85 PSI

The MAXIMUM pressure for the tires is 110 PSI which is entirely too high for your load.
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Old 11-13-2020, 03:23 PM   #11
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there is a pretty good you tube video on "RV street" if you really want to get into the weeds about determining tire pressure and it certainly supports what 16ACE27 says.

https://www.youtube.com/c/RVstreet/s...ire%20pressure

The videos are entertaining and often have some useful info.

No pressure!!
Rod
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Old 11-13-2020, 03:25 PM   #12
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[QUOTE=Sdkim;263872]
Quote:
Originally Posted by Lt Keefer View Post
What does the tire manufacturer

Attachment 27123

I think, according to the chart, 110 psi. But it just seems really high to me.
Your tire chart is per tire, here's the math.
78902=3945 (per tire) = 75lbs.
159904=3997.5 (per tire) = 75lbs.
As mentioned by EA37TS 75 may be a little low for good handling.

Thanks for the chart AND you weights
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Old 11-13-2020, 05:40 PM   #13
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Quote:
Originally Posted by Rod Belisle View Post
SDKim

there is a pretty good you tube video on "RV street" if you really want to get into the weeds about determining tire pressure and it certainly supports what 16ACE27 says.



https://www.youtube.com/c/RVstreet/s...ire%20pressure



The videos are entertaining and often have some useful info.



No pressure!!

Rod


Thank you so much.
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Old 11-13-2020, 05:56 PM   #14
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Quote:
Originally Posted by Bob Denman View Post
110 seems high...

But this is not your family sedan.

Give it a try.


Thank you.
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Old 11-13-2020, 05:57 PM   #15
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Originally Posted by wrapped View Post
My 2019 Challenger 37fh fully loaded 100gals water 80gal fuel and everything else fo fulltime living, frt 8200# rear 16040# I run 100psi all around and 2 1/2yrs up and down east coast no problems coach handles very well. Check the Michelin rv tire chart I think it's 80 ft 85rear. Check the yellow sticker on bottom panel on inside of screen door.


Thank you so much.
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Old 11-13-2020, 05:59 PM   #16
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[QUOTE=abjbrtd;263905]
Quote:
Originally Posted by Sdkim View Post

Your tire chart is per tire, here's the math.
78902=3945 (per tire) = 75lbs.
159904=3997.5 (per tire) = 75lbs.
As mentioned by EA37TS 75 may be a little low for good handling.

Thanks for the chart AND you weights
Yes for the front.
No for the rear - Dual ratings are the chart are per DUAL (two tires) and different than the single tire rating, so:
159902=7995 (per dual set) = 85lbs.
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Old 11-13-2020, 05:59 PM   #17
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[QUOTE=16ACE27;263900]
Quote:
Originally Posted by Sdkim View Post





OK, rough numbers from your axle weights are 4000 lbs per tire.

From your chart:

For singles (front) you can support 4070 lbs per tire at 75 PSI

For duals (rear) you can support 8080 lbs per pair at 85 PSI



The MAXIMUM pressure for the tires is 110 PSI which is entirely too high for your load.


Thank you so much.
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Old 11-13-2020, 06:30 PM   #18
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Originally Posted by Sdkim View Post
Thank you so much.


This You Tube video was very helpful. Thank you so much.
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Old 11-18-2020, 08:41 PM   #19
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Quote:
Originally Posted by Sdkim View Post
Hello everyone,

I have a 2020 Challenger 37FH. The tire size is 255/80 R22.5 XRV. The rv weighs in at 7,890 lbs front axle, 15,990 lbs rear axle.

I was advised to fill my tires at 110 psi for all six tires.

Does this sound right?

Thanks in advance.
With my made spreadsheet , it comes to Front 91 psi and rear 100 psi.

Disclaimer: you yourselfe are responcible for the given axleweights . And that is where it goes wrong often. Best is weighing per axle-end, second best per axle, in the loading ( also persons and pets) you drive with ( dont forget the water).

My advice is calculated with a formula that leads to higher pressure then the officially used, and I first add 10% to the load.
Your trucktires are most likely calculated in maximum load for 120kmph/75mph, and sometimes I even calculate for as if 160kmph/99mph. This together with the 10% adding, it gives highest reserve, with still acceptable comfort and gripp.
Will give those psi too. FRONT 102 PSI , REAR 103 PSI.
But this is still no 110 psi.
For this I lowered the single maxload for every 10kmph by 1 loadindex step, so front 138 -4=134
and rear from 135 to 134 only , because duall load already have lesser deflection.
That exlplaines the only 3 psi higher for rear, while front goes from 91 psi to 102 psi.

So if you are certain of the axleweights, first lower to front 100 and rear 105psi. Then if comfort is acceptable, dont go lower. Especially the 10 psi lower on front is noticed by driver and codriver in comfort,because seated close to the front-axle.
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Old 11-18-2020, 11:09 PM   #20
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The Michelin rv tire chart says 75lbs front 85lbs rear. for the weight you list . Go to Michelin rv tire chart find your tire size 255 80 22.5 , look at front tire single divide your front axle weight by 2 8,000-2=4000. Then find rear tire duel take your rear axle weight by 2 -16,000=8,000
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