Go Back   iRV2 Forums > MOTORHOME FORUMS > Class C Motorhome Discussions
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  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 05-13-2016, 12:02 PM   #15
Senior Member
Join Date: Jul 2014
Posts: 5,520
Tire and auto manufactures "ALL" recommend running the same pressure in ALL tires on the same axle.

Unless you can prove me wrong, I would strongly recomend you follow their recomdations.

Running different pressures on your right and left front tires will effect the handling in turns and effect the antilock brakes. It is just like running 2 diferent size tires.

twinboat 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 05-13-2016, 12:08 PM   #16
Senior Member
harleyjt's Avatar
Newmar Owners Club
Workhorse Chassis Owner
Join Date: Jan 2015
Location: Olive Branch, MS
Posts: 886
Originally Posted by mel s View Post
It is not unusual for the fronts to be inflated to a different pressure than the rears.
However all tires on the same axle should be inflated to the pressure recommended for the tire, (or tires), on that axle that is/are carrying the most weight.
'96 Safari

My point exactly. Front and rear may (or may not) be the same but side to side on same axle should always be the same. I think one of the other posts alluded (at least the way I read it) to inflating each side based on the weight of each respective side. Instead both sides should be inflated the same.

2005 Newmar Kountry Star gas 3742, Workhorse 8.1L w/Allison 5 speed.

Sent from my iPhone using iRV2 - RV Forum

2005 Newmar Kountry Star Gas 3742
Workhorse W24, 8.1L/Allison 5-spd
JT, Em & the boys, Kong and George (rescued grey tabbies)
harleyjt is offline   Reply With Quote
Old 05-13-2016, 04:08 PM   #17
Senior Member
Join Date: Mar 2016
Posts: 105
Even I am confused reading my own post!! Let's clarify...

Here's a chart from Michelin:


As is mentioned in the text above the chart, match the maximum corner weight (left or right on the same axle) and inflate the tires of that axle the same.

If you're so far off balance that you have a couple hundred pounds difference from left to right you might want to try to move stuff around.

If your scale only shows axle weight, divide by two, find that value on the chart, add 5psi and breathe easy.

My thinking was that the "radial" tire's driving radius is critical. Perhaps it doesn't change due to load as much as I thought. Also, when we're talking around 80psi, maybe +/- 5 is not a problem. All I know is that we started out putting 80psi everywhere and now we're at 65 up front and 70 in the dual rears. Much easier on the bumps and I didn't notice a change in gas consumption.

2010 Winnebago Aspect 28B
RogerRoll is offline   Reply With Quote
Old 05-14-2016, 06:15 AM   #18
Senior Member
Join Date: Feb 2011
Location: Snowbird - Waterford Mi and Citrus Springs Fl.
Posts: 3,350
Re: 80psi vs. 65frt/70rr, running minimum psi for better ride? Playing devil's advocate, not sure if you've considered potential side wall flex in cross wind/passing situations? Realize perfectly this is all a big set of compromises.
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake
ahicks is offline   Reply With Quote
Old 05-14-2016, 06:26 AM   #19
Senior Member
akadeadeye's Avatar
Join Date: Jul 2009
Location: Boerne, Texas
Posts: 1,368
Originally Posted by Lv2Roam2 View Post
There can be a significant difference between the left and right sides of the same axle. A conservative (higher safety margin) approach may be to use the max cold inflation pressures on your tire sidewalls to set your pressures until you get a true 4-corner weight. A less conservative approach is to use your axle weights and set the pressures about 5 - 10 pounds over the chart recommendation to help cover if one of the tires is significantly more loaded (but no higher than the max cold inflation pressure) until you can get the 4-corner weight.

Recommend you talk with the scale folks - they will often know who might have a scale with your needs. A call to local RV dealers may also be helpful. You're on the right track by paying attention to this issue. Safe travels...
This is excellent advice.

2009 Newmar 42 ft. Allstar 4188, Wheelchair Accessible, 400HP Cummins ISL, Allison 3000, Mastertow Dolly, '98 Riviera
akadeadeye is offline   Reply With Quote
Old 05-14-2016, 09:22 AM   #20
Senior Member
Commercial Member
Join Date: Mar 2010
Location: Akron, Ohio
Posts: 1,038
Trying to learn the actual load on each "corner" of a motorhome is the BEST policy.

HERE is a link to a worksheet that will help you learn the facts.

Class-C may be more balanced than Class-A but still can be hundreds of pounds out of balance side to side on an axle (Slides, location of generator , holding tanks etc).
Lacking corner weights I suggest a quick estimate of 45/55 % split side to side on each axle.

So once you have the numbers for each corner and you consult the charts for your tires. You will know the MINIMUM inflation for fronts (single loads) and rears (dual). Pay attention to the chart as some companies give the loads for each individual tire while others will give the load for the pair of duals. Dual position load capacity is always lower per tire than single position load capacity.

Using the heavier axle end number (or higher load end number if estimating) you now know the MINIMUM CIP setting for ALL tires on that axle.

I then suggest your set pressure to be the MINIMUM pressure + 10% .

Axle scale
F 5,000 R 10200
45/55 F 2250/2750 R 4490/ 5610 <corner loads
Tire loads F2250/2750 R 2245/2805

I would use the inflation for singles that supports AT LEAST 2750# and the inflation for duals that supports AT LEAST 2805# as my MINIMUM

My set pressure for all tires would be the MINIMUM +10%

Hope this clears things up.

Retired Design & Quality Tire Eng. Read my tire blog RVTireSafety.com to learn more about RV tires, valves & wheels. Read THIS post on why Tires Fail
Tireman9 is offline   Reply With Quote

tire pressure

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
Weighing Coach for Tire Pressure? Sky Pilot Class A Motorhome Discussions 21 06-02-2015 08:03 AM
Tire pressure prior to weighing BigOilJones Fleetwood Products Owner's Forum 14 10-16-2014 12:39 PM
Aspire Tire Pressure After Individual Weighing Kuppajoe Entegra Owner's Forum 26 01-24-2014 07:56 AM
Weighing our rigs for setting air pressures Max Hubrich Class A Motorhome Discussions 30 01-28-2009 03:52 PM
Weighing MH and tire pressure adjustment questions auntsis MH-General Discussions & Problems 7 07-23-2006 12:50 PM

» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 01:37 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.