Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A 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 08-29-2012, 07:18 AM   #1
Junior Member
Join Date: Jul 2012
Posts: 6
Newbie, first mh need new tire question

Hi all, picking up my 1st MH today! 2000 gulf steam sun voyager DP. It needs new tires. The current size is 245/75/22.5 gawr front 9000 back 16750 on the MH sticker. Went down to the local shop and they have toyo m154 in same size available. On toyo website it said max load 4675 lb single 4300 lb dual.
So do I just take 4675 x 2= 9350lb max for the front? And take 4300lb x 4 for the back?

If so why would I want to put these tire on since it max is only 350 lb over my front gawr? Would you go with different size so it could handle more weight? Or my understanding of weight is wrong?


reachkan 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 08-29-2012, 07:47 AM   #2
Senior Member
Sky_Boss's Avatar

Newmar Owners Club
Spartan Chassis
Join Date: Apr 2012
Posts: 5,579
A couple thoughts if I understand your situation...

First, make sure you get all 4 corner weights. You will need to make sure any wheel or set of wheels isn't individually overloaded for your tires. So, you need to make sure you do not exceed 4675# on either of your front wheels or 8600# on either of your rear set of wheels.

Second, use the highest weight on each axle to determine the air pressure to use for all wheels on the same axle.

Third, make sure the tires you are looking at are properly rated for your weight and speed.

I believe you could go a bit bigger on your tires but there are some factors to consider. The most important is the space between tires on duals. There are others here that have done that so I will let them comment on that since I have never done that myself and only have a basic understanding that it can be done.

The advantage of the bigger tires would be you can run your max axle weights and use a little lower tire pressure. For a gas chassis like mine, that can really help in ride comfort but for a DP with air suspension I'm not so sure such a change would be as noticeable. It would also give you some extra cushion if you find it hard to get your L & R sides weights nearly equal.

I would recommend that you get it weighed before you pick it up if you can talk the dealer into full water, fuel and LP. That will let you know just where you stand and whether or not there have been modifications after the RV was manufactured that affected its REAL weight. That could also help you in your decision of tire size/make.


Don, Sandee & GSD Zeus. Gardian Wings earned are GSDs Gunny (7/11/15) & Thor (5/5/15)
2006 DSDP 4320, Spartan MM IFS, 2013 CR-V, Blue Ox Avail, SMI AF1, Samsung 197R Refer.
Sky_Boss is offline   Reply With Quote
Old 08-29-2012, 10:22 PM   #3
Junior Member
Join Date: Jul 2012
Posts: 6
Thank you. I will do what you suggested.
reachkan is offline   Reply With Quote
Old 08-30-2012, 06:50 AM   #4
Moderator Emeritus
Gary RVRoamer's Avatar

Fleetwood Owners Club
Freightliner Owners Club
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 16,446
You did the arithmetic correctly. The 245/75's are adequate for your rig but don't have much extra capacity. They will have to be run at/near their max load psi, which might mean a slightly harsher ride.

I suspect your axles are actually loaded less than their max (GAWR), though. You may have more margin their than you think. A trip to the scales would be a good thing. Then you will know rather than guess about your safety margins.

If you feel you want extra capacity, you may be able to find the same size tire with a greater load range rating (more weight capacity), or you may be able to go up a bit in size. However, changing the tire size is not something to be done casually. You need in investigate a number of potential problems, e.g. front wheels might hit wheel well when turning, rear duals may be too close together, speedometer & odometer accuracy will be affected, tires may not fit properly on the existing wheels, etc.
Gary Brinck
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL
Gary RVRoamer is offline   Reply With Quote

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

» 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 10:28 AM.

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