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Old 12-03-2021, 12:48 PM   #15
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You'll find all you want to know at Roger Marble's RV tire site:

https://www.rvtiresafety.net/2011/03...and-roger.html

You'll want to read his posts that mention cold pressure.

Roger Marble, aka Tireman9 is a retired tire engineer and IRV2 member.
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Old 12-03-2021, 05:28 PM   #16
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I think TM9 wrote that article as reaction to next topic on RV forum, where I stated that you have to fill higher cold pressure when ambiŽnt temperature is fi 100 degrF , but can do with lower at fi 40 degrF , wich was the original question in that topic. Aboutv16 posts of mine to defend my statement, but roosted by the " specialists"

Saw Kid Gloves in this topic reacting, and could yust hold myself from writing that advice is for about 68 degrF.

http://https://www.irv2.com/forums/f...er-558461.html
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Old 12-04-2021, 02:18 AM   #17
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https://www.irv2.com/forums/f258/adj...er-558461.html
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Old 12-31-2021, 10:34 PM   #18
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tire PSI..

My tires had 110 psi when I bought the motor home. very rough ride, kinda slippery. our mh is pretty light 22,000 lbs. tires are rated at over 5k per tire at 115psi
consulted my brother the truck driver, he said same thing, weight / tire weight PSI. trade off is, mpg vs soft ride.
my tag says 80-85. i'm dropping them to 90 psi and will go from there, checking tire wear, ride, & mpg.
255/70R22.5

Dan.

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Old 01-09-2022, 05:45 PM   #19
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1. You weight your coach, front and rear weights.
2. You contact the tire maker, and get a weight/pressure chart (usually these are available online...)
3. You inflate the tires to be the step above your measured weights, front and rear.

End or discussion! The chart is for maximum weight in your RV, and you may not have maximum weight. The maximum on the tire is just that: the maximum that tire can safely withstand at maximum weight for that tire!
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Old 09-14-2022, 11:14 PM   #20
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weigh your rig ! ! ! !
follow the tire weight / psi recommendations published for THAT tire.
previous owner had 110 psi in all tires. it was rough and slippery ride. when a semi would pass it would about blow my rig into the ditch !.. so correlating weight / psi I found that I could safely run 95 psi and it is a much softer ride, wayyy batter traction, and still safely within the weight limit . psi of the tire.
my rig weighs 22000 max.. ( and fully loaded on the scale 21898) max weight of the tires at max 115 psi is 31300lbs. about 10,000 lbs more tire than rig. so I tested to 80lbs. huge change in performance. way more sticky, but, huge increase in drag... I found at 95 psi they still roll easy and still sticky enough the passing semi is a mute point. and way smoother ride.
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Old 09-15-2022, 02:34 PM   #21
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Calculated for post#20.
Gave 85psi rear and 95psi front.
Here a picture of my made filled in spreadsheet.

Mind the 10% reserve used, needed for unequal weight R/L on the axle, inacuracies in measuring weight and pressure, pressuredrop in time, etc.and the specifications of tire give max speed 75mph is speedcode L.
So dont drove faster, notbeven for a minute.

I also calculated highest pressure atvwich comfort and gripp is still acceptable to my concusions in time.
And for that I use that 10% reserve added, and loadindexes lowered by 4 steps to give the tire a deflection needed for Q speedrate max 99mph.
Mayby for a semi truck tire this is exagerated, so value this as you think wise.
Gave front 108psi and rear 96 psi.

My advice is to always take about 2 speedsteps higher so 12 mph higher then your maximum used speed as extra reserve.
You yourselfes know best what your used max speed is.
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