Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Closed Thread
  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 09-16-2017, 12:14 PM   #1
Senior Member
 
Golfer Guy's Avatar
 
Monaco Owners Club
Join Date: Dec 2014
Location: out west
Posts: 312
Weight & tire PSI question

what would the proper PSI be for my tires:

Front Toyo M144 22.5/295/80R 11,760 lbs. front axle
Rear Duel Goodyear 670RV 22.5/295/80R 22,520 lbs.

Towing a Jeep Wrangle 4640 lbs.

For those of you in the know.

I have been keeping all my tires at 100 PSI.

Thanks
__________________

__________________
2006 38' Beaver Monterey
2014 Jeep Wrangler Toad
Golfer Guy is offline  
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 09-16-2017, 12:26 PM   #2
"Formerly Diplomat Don"
 
Dutch Star Don's Avatar
 
Newmar Owners Club
Join Date: Apr 2005
Location: Moorpark, Ca.
Posts: 9,313
Here's the chart.....http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

Yours falls into an usual category where the rear calls for more air than the front. 100 front and 105 rear. USUALLY, the rears are inflated 5-15 pounds less.

Whoops......I missed the Toyo's on the front. Seems like pressures are still the same.
__________________

__________________
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab
Dutch Star Don is offline  
Old 09-16-2017, 12:31 PM   #3
Senior Member
 
FastEagle's Avatar
 
Join Date: Sep 2009
Posts: 819
You will find the information you're looking for in the reference provided below.

https://www.toyotires.com/media/1489/tiresafety.pdf
FastEagle is offline  
Old 09-16-2017, 12:39 PM   #4
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,730
From the load charts: Front 100-105, Rear 105-110. This is a good start, but a four position weight would be better. What are the GAWR front and rear?
__________________
2013 43 QGP Allegro Bus
Crasher is offline  
Old 09-16-2017, 10:07 PM   #5
Senior Member
 
Golfer Guy's Avatar
 
Monaco Owners Club
Join Date: Dec 2014
Location: out west
Posts: 312
Quote:
Originally Posted by Crasher View Post
From the load charts: Front 100-105, Rear 105-110. This is a good start, but a four position weight would be better. What are the GAWR front and rear?
GAWR Is 12,800 front and 23,000 rear. I'm very close to the limit with 100 gal of water, 40 gal propane (which I will never use up) and full gas tank 109 gal which I was when weighed.

Probably should add 10lbs to the rear. 100 front 105 rear whould be better perhaps.

Thanks all for the input.
__________________
2006 38' Beaver Monterey
2014 Jeep Wrangler Toad
Golfer Guy is offline  
Old 09-17-2017, 06:10 AM   #6
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,730
Quote:
Originally Posted by Golfer Guy View Post
GAWR Is 12,800 front and 23,000 rear. I'm very close to the limit with 100 gal of water, 40 gal propane (which I will never use up) and full gas tank 109 gal which I was when weighed.

Probably should add 10lbs to the rear. 100 front 105 rear whould be better perhaps.

Thanks all for the input.
Keep in mind that the axle weight might not be equally divided between sides. It's not uncommon to see an axle 1000# heavier on one side that the other. What does that do to the psi requirement?? Only a four position weight can get you the correct pressures.
__________________
2013 43 QGP Allegro Bus
Crasher is offline  
Old 09-17-2017, 06:22 AM   #7
Ex Millwright / Army Vet
 
marjoa's Avatar


 
Join Date: Aug 2016
Location: Livingston, TX
Posts: 1,411
It's also a good practice and most folks here do this, is once you determine your proper PSI add at least an additional 5lbs. for a fudge factor and possible weight creep.
__________________
TEAM Martin & Joanie...and Wookie (our wonderful Yorkie)
2012 WGO Vista 35F, 5 ST, Toyo M122's/duallys, Centramatics (all around), TPMS, ScanGuage II, Safe T Plus, SS Rear Trac Bar, Koni FSD's, BG Fluids, Toad 2017 FORD Fiesta, Escapees
Making Traveling, FTing and Our Motorhome "GREAT AGAIN".
marjoa is offline  
Old 09-17-2017, 12:13 PM   #8
Senior Member
 
Golfer Guy's Avatar
 
Monaco Owners Club
Join Date: Dec 2014
Location: out west
Posts: 312
Quote:
Originally Posted by Crasher View Post
Keep in mind that the axle weight might not be equally divided between sides. It's not uncommon to see an axle 1000# heavier on one side that the other. What does that do to the psi requirement?? Only a four position weight can get you the correct pressures.
I had a four corner weight done at Escapees a year ago or so. The weights were as follows:

R Front 5920 R Rear 11250
L Front 5850 L Rear 10400

then 11,800 21,650
now 11,700 22,520

New different brand tires (Toyo) in the front since then and weights have increased a bit over time. Added two batteries to the passage rear side. Towing a different heavier car now too. Escapees said 95 in the front and 100 in the rear back then.

Thanks for the input guys.

Steve
__________________
2006 38' Beaver Monterey
2014 Jeep Wrangler Toad
Golfer Guy is offline  
Old 09-18-2017, 03:27 AM   #9
Senior Member
 
FastEagle's Avatar
 
Join Date: Sep 2009
Posts: 819
Tire industry standards are consistent across the board. Different manufacturers may say it differently but in the end they all mean the same thing.

If your Motor Home has a federal certification label installed by the final stage manufacturer and it has recommended cold inflation pressures for the tires depicted on it, it was built to FMVSS standards and all industry standards applicable to FMVSS standards apply.

Many MHs are fitted with large commercial grade tires. That does not mean commercial regulations can be applied. Commercial standards do not have recommended cold inflation pressures.

Tire industry standards are found in just about all major tire manufacturer’s publications or in PDF files on the WWW. Here is a quote from page #7 in the attached reference.

“The placard indicates the minimum inflation pressures which must be maintained.”

http://www.michelintruck.com/assets/...e_Warranty.pdf
FastEagle is offline  
Old 09-18-2017, 08:10 AM   #10
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,730
Quote:
Originally Posted by FastEagle View Post
Tire industry standards are found in just about all major tire manufacturer’s publications or in PDF files on the WWW. Here is a quote from page #7 in the attached reference.

“The placard indicates the minimum inflation pressures which must be maintained.”

http://www.michelintruck.com/assets/...e_Warranty.pdf
Keep in mind that the manufacturer needs to protect their behinds, so they assume that the motorhome is loaded to the maximum GVWR all the time. Those are the psi values on the placard. Many MH's, especially those with tag axles are never at the GVWR. In every case the only way to achieve the best ride, handling characteristics and tire wear is to go by the tire manufacturers load inflation charts.
__________________
2013 43 QGP Allegro Bus
Crasher is offline  
Old 09-18-2017, 12:58 PM   #11
Senior Member
 
Monaco Owners Club
Join Date: Aug 2011
Posts: 303
Quote:
Originally Posted by Golfer Guy View Post
I had a four corner weight done at Escapees a year ago or so. The weights were as follows:

R Front 5920 R Rear 11250
L Front 5850 L Rear 10400

then 11,800 21,650
now 11,700 22,520

New different brand tires (Toyo) in the front since then and weights have increased a bit over time. Added two batteries to the passage rear side. Towing a different heavier car now too. Escapees said 95 in the front and 100 in the rear back then.

Thanks for the input guys.

Steve
Good job getting weighed. Here's the Toyo inflation tables:
https://toyo-arhxo0vh6d1oh9i0c.stack...ion_tables.pdf

I use the same tires. I add 5 psi to the values given for the weights.

HTH,
__________________
Bob Covey
Home: 2003 Monaco Executive 43 SDDS, ISM
bobcovey is offline  
Old 09-18-2017, 02:53 PM   #12
Senior Member
 
FastEagle's Avatar
 
Join Date: Sep 2009
Posts: 819
Quote:
Originally Posted by Crasher View Post
Keep in mind that the manufacturer needs to protect their behinds, so they assume that the motorhome is loaded to the maximum GVWR all the time. Those are the psi values on the placard. Many MH's, especially those with tag axles are never at the GVWR. In every case the only way to achieve the best ride, handling characteristics and tire wear is to go by the tire manufacturers load inflation charts.
Maybe the Vehicle manufacturer is protecting their "behinds". In compliance with FMVSS standards they were told to do so by setting recommended cold inflation pressures that are appropriate for the GAWR. Tire industry standards support that statement by saying to never use inflation pressures below vehicle manufacturer recommendations.

Tire manufacturers do not set tire pressures for vehicles built using FMVSS standards. They provide charts/tables for vehicle manufacturers to use during tire selection and fitments. After market plus sized tires have their inflation pressures set to provide a load capacity equal to or greater than the OE tires provided.

It's important to remember that FMVSS standards are only going to meet approved minimal safety standards. So, an owner can always increase their tires cold inflation pressures to gain load capacity reserves. Not all fitments will provide that option and wheel and tire maximums cannot be safely exceeded.

Read FMVSS 571.120 paragraph S5.3.1.
FastEagle is offline  
Old 09-18-2017, 03:30 PM   #13
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,730
Quote:
Originally Posted by FastEagle View Post
Maybe the Vehicle manufacturer is protecting their "behinds". In compliance with FMVSS standards they were told to do so by setting recommended cold inflation pressures that are appropriate for the GAWR. Tire industry standards support that statement by saying to never use inflation pressures below vehicle manufacturer recommendations.

Tire manufacturers do not set tire pressures for vehicles built using FMVSS standards. They provide charts/tables for vehicle manufacturers to use during tire selection and fitments. After market plus sized tires have their inflation pressures set to provide a load capacity equal to or greater than the OE tires provided.

It's important to remember that FMVSS standards are only going to meet approved minimal safety standards. So, an owner can always increase their tires cold inflation pressures to gain load capacity reserves. Not all fitments will provide that option and wheel and tire maximums cannot be safely exceeded.

Read FMVSS 571.120 paragraph S5.3.1.
OK. You do it your way and I'll continue to use the load inflation tables as I have been for 25 years with good results even when the load calls for a psi below the placard figure.
__________________
2013 43 QGP Allegro Bus
Crasher is offline  
Old 09-18-2017, 03:37 PM   #14
Senior Member
 
FastEagle's Avatar
 
Join Date: Sep 2009
Posts: 819
Quote:
Originally Posted by Crasher View Post
OK. You do it your way and I'll continue to use the load inflation tables as I have been for 25 years with good results even when the load calls for a psi below the placard figure.
It's not MY way. It's the industry's acceptable and safest way.
__________________

FastEagle is offline  
Closed Thread

Tags
weight



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
Determine tire psi using MH weight? tripntx Class A Motorhome Discussions 10 12-29-2016 10:44 AM
Dry (shipping) Weight = Axle Weight + Pin Weight? Old Bill Trailer Towing and Tow Vehicles Discussion 11 12-05-2016 05:58 PM
Can Anyone Help Me Figure Out These Weights & Tire PSI Tytlfamily Class A Motorhome Discussions 16 08-20-2015 09:04 PM
Air Horn works low Psi but not full psi? hkindle Spartan Motorhome Chassis Forum 4 01-21-2014 08:46 AM
Weight vs Tire psi - 2005 Alpine Coach 36' FDDS tjshively Alpine Coach Owner's Forum 3 11-13-2012 03:06 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:40 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.