RV Trip Planning Discussions

Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Trailer Towing and Tow Vehicles Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 07-09-2019, 03:53 AM   #1
Senior Member
 
Brenwol1's Avatar
 
Join Date: Jun 2018
Location: Chickamauga, GA
Posts: 115
Pressure

I know this dead horse has been beaten but I have to put this out there. A little background...

Just picked up a new tt on Saturday.and the walk-thru tech advised us to keep the tires at 60 psi. They are rated for 65 psi cold.

Now before everyone tears into this tech, he was an experienced (45 years) rv'er. Very knowledgeable and nice. A good amount of valuable information. I agree with 99% of what he said.

I know this can be a religious discussion, so let me pose the question this way:

What this the technical/scientific reason to to run the tires at max cold pressure versus 5 lbs under to allow for expansion?

If I'm going to hold a position/opinion, I want to make sure it's an informed one.

Thanks.
__________________

Brenwol1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-09-2019, 05:48 AM   #2
Senior Member
 
Join Date: Feb 2012
Posts: 141
There are a ton of folks much smarter than me who have done the engineering on tires. I would look to see if there is a minimum spec on the tire. Then I would go ahead and inflate to the max, maybe a hair under but not over. Just my opinion.
__________________

Spoonsize is online now   Reply With Quote
Old 07-09-2019, 06:49 AM   #3
Senior Member
 
Join Date: Jul 2000
Location: Yankton, SD
Posts: 301
Max inflation pressure is just that, dont over think it. That being said the carrying cap. of the tire depends on inflation pressure up to the Max pressure. The manufacture Designed the tires, you dont need to allow for expansion. Less pressure less carrying capacity.
__________________
George
2011 Ford F350 DRW
2015 Mobile Suites 41RSSB4
Fulltimer is offline   Reply With Quote
Old 07-09-2019, 06:57 AM   #4
Senior Member
 
sirtate's Avatar
 
Join Date: Mar 2019
Posts: 172
It may just to cover variations in pressure gauges.

(Inflate to 60, just in case your gauge reads a bit low)
sirtate is offline   Reply With Quote
Old 07-09-2019, 09:38 AM   #5
Senior Member
 
Join Date: Mar 2019
Posts: 334
Quote:
Originally Posted by Brenwol1 View Post
I know this dead horse has been beaten but I have to put this out there. A little background...

Just picked up a new tt on Saturday.and the walk-thru tech advised us to keep the tires at 60 psi. They are rated for 65 psi cold.

Now before everyone tears into this tech, he was an experienced (45 years) rv'er. Very knowledgeable and nice. A good amount of valuable information. I agree with 99% of what he said.

I know this can be a religious discussion, so let me pose the question this way:

What this the technical/scientific reason to to run the tires at max cold pressure versus 5 lbs under to allow for expansion?

If I'm going to hold a position/opinion, I want to make sure it's an informed one.

Thanks.
Max. cold inflation pressure is just that, when the tires are cold and haven't been driven nor baked in the sun for hours. If max pressure is 65 psi you can set it to that COLD. Manufacturers allow for the expansion of a hot tire, some can go 10 psi or more above cold pressure.

If your tire is rated for much more cargo capacity than is needed running it lower than max makes for a comfier,less bouncy or harsh ride. I switched the load range D tires to load range E tires on our 5er. I ran them at 80 psi cold for a long time but have since found 70 psi is plenty adequate and much less stuff gets rattled around on harsh roads.
__________________
2011 GMC Sierra 3500HD dually gas 6.0

2006 Lakota 29RKT
kdauto is offline   Reply With Quote
Old 07-09-2019, 09:46 AM   #6
Senior Member
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Nowhere, now here. Freedom!
Posts: 4,336
ST type tires must be inflated to their max cold pressure. Other tires might have a load table, but then you need to know your exact weight. Max inflation is safer than guessing a number less than that.
__________________
ORV 19B Full Timer Since '15, '14 Ram 2500 Diesel and a GSD. As of July 14, I'm in Yakima WA for a tax paying job so I have an opinion about things Headed to Aberdeen WA soon
de K7NOL 146.52Mhz Safety? (CLICK ME!)
1bigmess is offline   Reply With Quote
Old 07-09-2019, 10:03 AM   #7
Senior Member
 
Join Date: Oct 2016
Posts: 1,720
This horse can’t be killed.

Do you know the weight of your trailer?

The maximum pressure, as stated on the tire, will support the maximum load, as stated on the tire.

Did you ask the mechanic how he determined that 60psi was the proper pressure?

Inflating to maximum pressure without knowing the weight of the vehicle is simply making an uninformed decision.
__________________
2005 Alpine Coach 36MDDS
2015 Grand Cherokee Diesel
RVPioneer is online now   Reply With Quote
Old 07-09-2019, 10:17 AM   #8
Senior Member
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Nowhere, now here. Freedom!
Posts: 4,336
Quote:
Originally Posted by RVPioneer View Post
Inflating to maximum pressure without knowing the weight of the vehicle is simply making an uninformed decision.
Not if the tires on the OPs travel trailer are ST type tires on a multiple axle setup.

https://www.rvtravel.com/tire-inflat...nterply-shear/
__________________
ORV 19B Full Timer Since '15, '14 Ram 2500 Diesel and a GSD. As of July 14, I'm in Yakima WA for a tax paying job so I have an opinion about things Headed to Aberdeen WA soon
de K7NOL 146.52Mhz Safety? (CLICK ME!)
1bigmess is offline   Reply With Quote
Old 07-09-2019, 10:19 AM   #9
Senior Member
 
Join Date: May 2019
Posts: 278
Quote:
Originally Posted by Brenwol1 View Post

What this the technical/scientific reason to to run the tires at max cold pressure versus 5 lbs under to allow for expansion?

If I'm going to hold a position/opinion, I want to make sure it's an informed one.

Thanks.

Tires are tested and rated under laboratory conditions. There aren't potholes, gravel in turns, tiregators, beer bottles, road heaves, misaligned bridge expansion joints, or anything like that. Basically, tires are rated based on race track conditions. You're not on a track, you're out in the real world. The 5 pounds will give you a little softer ride, and will give your tires a little buffer to help with potholes and road debris.


Do a little experiment. Get a bag of balloons and take two of them out of the bag. Blow one up just before it pops and tie it. Then blow up the other one the same way, but let 10% of the air out then tie it. Now hit the balloons (tires) on the corner of your table (pothole) and see which one pops first.
__________________
2014 F350 DRW 6.7L CC FX4 King Ranch Ruby Red Metallic 148,000 Miles 4,200 Hours
2018 Cherokee Grey Wolf 29TE | Because I'm home, no matter where I am.
2018 Honda CB650F | Because the truck leans the wrong way when I turn.
Itchytoe is offline   Reply With Quote
Old 07-09-2019, 10:35 AM   #10
Senior Member
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Nowhere, now here. Freedom!
Posts: 4,336
I'd like to see everyone that is giving recommendations for lower than max tire pressure to cite authoritative sources for why this is a good idea on a trailer that likely has ST type tires.
__________________
ORV 19B Full Timer Since '15, '14 Ram 2500 Diesel and a GSD. As of July 14, I'm in Yakima WA for a tax paying job so I have an opinion about things Headed to Aberdeen WA soon
de K7NOL 146.52Mhz Safety? (CLICK ME!)
1bigmess is offline   Reply With Quote
Old 07-09-2019, 11:06 AM   #11
Senior Member
 
Join Date: Oct 2016
Posts: 1,720
Quote:
Originally Posted by 1bigmess View Post
I'd like to see everyone that is giving recommendations for lower than max tire pressure to cite authoritative sources for why this is a good idea on a trailer that likely has ST type tires.
We all have to choose our “experts”. The expert blogger that you provided a link to also advises motorhome owners to inflate their tires to at least 10% above what is recommended by the tire manufacturers inflation chart.

Can you cite a manufacturer that recommends over-inflating their tires by 10% or more?
__________________
2005 Alpine Coach 36MDDS
2015 Grand Cherokee Diesel
RVPioneer is online now   Reply With Quote
Old 07-09-2019, 11:15 AM   #12
Senior Member
 
Join Date: Nov 2015
Posts: 10,043
Hey OP........


Load up that trailer with everything to go on camping trip
60 psi in tires

Take some sidewalk chalk and rub a wide stripe of chalk across tire thread
Then pull trailer Straight forward for 25' (parking lots are good place)
Check the chalk mark----
Rubbed off on edges (inside/outside) tire under inflated
Rubbed off in center area --tire over inflated
Rubbed off across the thread ----go camping
__________________
Is it time for YOUR medication or MINE
2007 Dodge 3500 w/Tractor Motor & NUWA 5vr
US NAVY---USS Decatur DDG-31
Old-Biscuit is offline   Reply With Quote
Old 07-09-2019, 11:16 AM   #13
Senior Member
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Nowhere, now here. Freedom!
Posts: 4,336
Quote:
Originally Posted by RVPioneer View Post
We all have to choose our “experts”. The expert blogger that you provided a link to also advises motorhome owners to inflate their tires to at least 10% above what is recommended by the tire manufacturers inflation chart.

Can you cite a manufacturer that recommends over-inflating their tires by 10% or more?
(Please don't shoot the messenger )

I'm not making any claims about MH tires. You should ask Mr Marble your questions about his opinions.

I'm not claiming any expertise, education, or training. I just know that dual axle trailer tires suffer from forces that are far greater than most any other road tire application, and since Mr Marble has taken apart and done post mortem exams on more tires than I'll ever use, you should ask him for the reasons for his opinions. All I can do is try to make sure that I find people that are as expert in their fields as possible for info on how to use certain things in specific applications.

And I always try to cite an authoritative source specific to the facts of an issue if I have one.
__________________
ORV 19B Full Timer Since '15, '14 Ram 2500 Diesel and a GSD. As of July 14, I'm in Yakima WA for a tax paying job so I have an opinion about things Headed to Aberdeen WA soon
de K7NOL 146.52Mhz Safety? (CLICK ME!)
1bigmess is offline   Reply With Quote
Old 07-09-2019, 11:44 AM   #14
Senior Member
 
Brenwol1's Avatar
 
Join Date: Jun 2018
Location: Chickamauga, GA
Posts: 115
Quote:
Originally Posted by RVPioneer View Post
This horse can’t be killed.

Do you know the weight of your trailer?

The maximum pressure, as stated on the tire, will support the maximum load, as stated on the tire.

Did you ask the mechanic how he determined that 60psi was the proper pressure?

Inflating to maximum pressure without knowing the weight of the vehicle is simply making an uninformed decision.
Just got the trailer a few days ago so I don't have a loaded weight. Dry weight with 1/3 tank fresh and full propane was about 5,200.

Based on what we loaded in the trailer we just traded, it will weight around 6,000 +/- a couple of hundred lbs.

So, when I check the tire specs, that weight will be more or less distributed between four tires for purposes of determining the tire capacity, correct?
__________________

Brenwol1 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Low oil pressure | erratic oil pressure | inconsistant oil pressure GlennLever Cummins Engines 45 08-28-2014 08:24 AM
Front axle air pressure shows high and low pressure alarm sounds Restless Newmar Owner's Forum 4 10-04-2010 10:28 PM
Water pressure regulator - low pressure Ggrvusa MH-General Discussions & Problems 2 12-26-2009 08:18 AM
Water Pressure This is what I am using!!! But looking for a Pressure regulator??? Latitude MH-General Discussions & Problems 17 06-13-2008 05:35 AM
Doran/Pressure Pro Tire Pressure Monitor. Roam America Gear and Product Discussions 19 01-04-2008 10:56 AM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:02 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.