Go Back   Montana Owners Club - Keystone Montana 5th Wheel Forum > GENERAL DISCUSSIONS > TIRES, Montana Tires
Click Here to Login

Thread Tools Display Modes
Old 07-28-2016, 03:36 PM   #1
Montana Fan
Join Date: Oct 2011
Location: Vancouver
Posts: 180
M.O.C. #11886
Tire Math - Inflation vs axle ratings

Tire gurus -
I have a 2008 3500 dually. Frt GAWR = 4860lbs, 2430/ tire. RR GAWR = 8200 lbs, 2050/tire. The inflation sticker says 66lbs for the fronts, 60 for the rr.

I am running Toyo Open Country H/D Tuff Duty tires.
According to the Toyo load inflation chart -
(single) 60 psi = 2280, 65=2405, 70=2540, 75=2670, 80=2755
(dual) 60=2075, 65=2205, 70=2310, 75=2430, 80=2535

Given the above, I have run the fronts @ 70 psi. And the rears @ 60 psi. (Eases the ride when not towing and I am a bit lazy when it comes to fighting with the inside dually.)
But I read here and in other forums, and have been told more than once to inflate the rr's to 80 when towing. Why bother inflating the tires beyond the axle capacity?

sapest is offline   Reply With Quote
Old 07-28-2016, 03:51 PM   #2
Montana Master
rohrmann's Avatar
Join Date: Oct 2012
Location: Box Elder
Posts: 3,253
M.O.C. #12947
Looks to me that the 66 psi front and 60 psi rear is perfect. Best to go by the vehicle maker's pressure suggestions.
Bob & Becky
2012 3402RL
2012 Chevy 2500HD D/A CC 4WD
rohrmann is offline   Reply With Quote
Old 07-28-2016, 04:38 PM   #3
Montana Fan
Join Date: Apr 2009
Location: big pine
Posts: 128
M.O.C. #9253
I keep thinking back to the ford-exploder firestone tire problem and would go with the tire company.
catskiner is offline   Reply With Quote
Old 07-28-2016, 04:40 PM   #4
Montana Master
Join Date: Feb 2005
Location: Haysville
Posts: 3,741
M.O.C. #3085
Just throwing this to the discussion. My dually has 60 psi for both front and back on the door sticker. My Uniroyals say max inflation 80 psi on the sidewall. Some don't understand what the difference between max inflation and door stick psi means. If I were to inflate my rears to 80 psi ... I'd never keep her on the road as it drives like I'm on bear grease. If I were to keep my rears inflated to 60 psi ... the center of the tire wears noticeably quicker than the outside. I run my fronts at 60 psi and the rears at 55 psi with good tread wear for both. My measured pin weight is 2340#.
dieselguy is offline   Reply With Quote
Old 07-29-2016, 02:10 AM   #5
Montana Master
Join Date: Mar 2012
Location: Davison
Posts: 767
M.O.C. #12331
Inflating to maximum rated tire pressure lessens sidewall flex on the tires. The pressures on the load rating sticker are based on the OEM tires. I will always inflate to the tire manufacturers recommendation. If you have a failure, that's who you're going to deal with not the manufacturer of the truck-unless the tire is in OEM warranty.
bethandkevin is offline   Reply With Quote

Thread Tools
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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tire Inflation PSFORD99 General Discussions about our Montanas 10 01-23-2013 03:30 PM
Axle Ratings? Art What I'd like to say if... 5 05-01-2012 11:12 AM
Tire Load Math - A Second Opinion? KathyandDave Tow Vehicles & Towing 9 06-04-2009 06:04 PM
Montana Tire Ratings lasater General Discussions about our Montanas 3 03-29-2008 05:20 AM
Tire Inflation Question RKassl General Discussions about our Montanas 14 07-18-2005 11:31 AM

Powered by vBadvanced CMPS v3.2.3

This website is not affiliated with or endorsed by Montana RV, Keystone RV Company or any of its affiliates. This is an independent, unofficial site.

All times are GMT -6. The time now is 09:52 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.