Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

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.
  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 05-14-2016, 05:22 PM   #1
Senior Member
Thor Owners Club
Join Date: Jul 2015
Posts: 207
275/70/22.5 vs 275/80/22.5

I've got 275/70/22.5 Goodyear tires on our 40' DP, I have been seeing 275/80/22.5 tires on a lot of the new rigs. I am speculating the ride is much better with the 80 series sidewall. Has anyone done the swap? I don't think clearance would be an issue. What about minimum dual wheel spacing in the rear?
Agaveguy is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! 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 05-14-2016, 05:26 PM   #2
Senior Member
JCM's Avatar
Workhorse Chassis Owner
Triple E Owners Club
Join Date: Nov 2004
Location: Williams Lake,BC Canada
Posts: 1,226
I believe the "70" or "80" are the heights of the tires. It is the 275 vs 290 I would worry about for rear clearance.
I just bought a set of 275-8--22.5. My old ones aged out. They ride like a dream.
2020 Triple E Wonder RTB
JCM is offline   Reply With Quote
Old 05-14-2016, 05:44 PM   #3
Senior Member
Thor Owners Club
Join Date: Jul 2015
Posts: 207
Yes, the 70 and 80 are the aspect ratio, that # means the percentage of the width in sidewall height.

Anyone think it matters much if I do the fronts for now and the rears later? Would anyone make the switch for ride comfort alone if the existing tires are in good shape?
Agaveguy is offline   Reply With Quote
Old 05-14-2016, 05:54 PM   #4
Senior Member
wb7auk's Avatar
National RV Owners Club
Join Date: Feb 2012
Location: Spokane Valley, Wa
Posts: 1,987

The above link with give you the difference in tires.
1999 Trade Winds 7371 Cat 3126B w/current upgrades
1990 D 250 Dodge Ram Cummins Turbo
wb7auk is offline   Reply With Quote
Old 05-14-2016, 07:20 PM   #5
Senior Member
slowmachine's Avatar
Nor'easters Club
Freightliner Owners Club
Holiday Rambler Owners Club
Join Date: Dec 2014
Location: Alton, NH
Posts: 1,653
275/70/22.5 vs 275/80/22.5

I would ignore the mostly-wrong tire calculators on various websites and use the tire manufacturers' published specs to compare tires.

275/70R22.5, 265/75R22.5 and 255/80R22.5 are, functionally, the same diameter tire. They are all within a range of about 10 revolutions per mile. 275/80 is a larger tire and will affect the overall gearing and driving characteristics of the motorhome.

I changed from 255/80 to 275/70 and have no complaints.
2000 HR Endeavor 40PBD, Freightliner XC, CAT 3126B
Gut/Remodel Thread
slowmachine is offline   Reply With Quote
Old 05-15-2016, 08:42 AM   #6
Moderator Emeritus
Gary RVRoamer's Avatar

Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 25,066
Use the tire manufacturer specs for dual spacing. That cannot be calculated with an generic tire compare tool - it's an engineering analysis. In all probability, though, those two sizes will be dual-spacing compatible if they are the same manufacturer.

The extra height of the 80's will increase the diameter slightly, which in turn reduces the rev/mile a tiny bit, but probably not enough to be concerned. Again, the revs/mile comparison will tell you the exact impact of the speedometer/odometer. The small amount of extra height should not be an issue in the wheel well either, unless it is already very tight there.

No problem changing fronts and rears at different times, as long as all tires on the same axle are the same.

Would anyone make the switch for ride comfort alone if the existing tires are in good shape?
Absolutely not. I sincerely doubt you will be able to tell the difference. A couple of psi more or less in the tires will have far more effect than a 0.10 difference in section height ratio. For a 275 width, we are talking only 1/10 of an inch!
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
275/70 vs 275/80 tires on an 04 Dutch Star travelers1214 Newmar Owner's Forum 5 09-11-2009 01:18 PM
switched 275/70/22.5's for 275/80/22.5's beaverjim MH-General Discussions & Problems 2 04-16-2008 03:40 AM
Poor downshift with Cruise Control Cummins 275 EasyDoesIt Winnebago Industries Owner's Forum 2 04-11-2008 03:34 PM
275/70R22.5 or 305/70R22.5 on 02 Dutch Star walkingplow Newmar Owner's Forum 11 08-23-2007 06:56 PM
275 cummins oil change Xeroid Winnebago Industries Owner's Forum 3 01-18-2005 10:40 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 06:46 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.