|
11-20-2012, 09:30 AM
|
#1
|
Senior Member
National RV Owners Club Ford Super Duty Owner Carolina Campers
Join Date: Jul 2012
Location: Wilmington, NC
Posts: 858
|
Tire pressure - what am I missing??
Really confused here by the tire pressure tables, my weight and load capacities....
I have 2004 Seabreeze, class A model 1341 gas MH. Has Ford chassis. GVWR is 22,000. Empty is 17,300, my weights ready to go are 6375 front and 12,365 rear. Not much gear and don't keep tanks full...anyway, here come questions.
Per Goodyear load chart 245/70r19.5 manufactured after 2006, single load rate at 90 psi is 3890 and dual at 90 psi is 3655, so front load at 90 psi is 2X3,890=7,780!!! and rear is 4X3,655=14,620!!
So if I am reading right, even at 90 psi, these tires are way over where I need to be, and over the GVWR for vehicle, which is 7,500 front axle and 14,500 rear axle.
When I bought this the tires were at 105 PSI and ride was very harsh, I had alignment, balance (Fronts) and shaved to correct out of round, lowered tires to 90 PSI and ride was improved tremendously.
Should I actually lower the pressure below 90 psi, or just keep them there for a safe margin, lowering to 85 would give me 7,480 front and 14,060 rear, still good margin and still very close to GVWR, 21,540 vs. 22,000, and maybe a little better ride.
Curious where you have yours or what you think here.
Many thanks, and Happy Thanksgiving
|
|
|
|
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!
|
11-20-2012, 09:38 AM
|
#2
|
Senior Member
Join Date: Oct 2011
Posts: 1,136
|
I would stay at 90 psi. Went through 3 MH and never had a problem with 90. Tires wear even and as you have already found out you get a better ride.
|
|
|
11-20-2012, 09:39 AM
|
#3
|
Senior Member
Freightliner Owners Club
Join Date: Apr 2007
Posts: 432
|
trode sounds like you have a good understanding of tire psi chart for your rig. With those wts 85 psi will work fine and will improve your ride. good luck and happy rving.
__________________
2001 Horizon 2004 jeep GC
|
|
|
11-20-2012, 09:49 AM
|
#4
|
Senior Member
Join Date: Dec 2010
Location: sioux falls sd
Posts: 322
|
If you do drop below the recommended 90 PSI I would highly recommend TPMS. Also I think if you drop to 85 you should be fine because once tires heat up they will be above 90. However I would stay as close to 90 as you can if possible.
__________________
2009 Dodge ram 2500 Cummins Mega Cab
1999 R29RL King of the road.
3 kids and a beautiful wife.
|
|
|
11-20-2012, 10:02 AM
|
#5
|
Senior Member
Winnebago Owners Club Freightliner Owners Club
Join Date: Aug 2005
Location: Nashua, NH
Posts: 2,689
|
Without individual wheel position weights you'll want to allow a little more margin in case you have an imbalance side to side. My practice is to go with the pressure from the charts plus 5 psi. The extra gives me a bit of margin so I don't have to worry about dropping below the required minimum with change of temperature, etc. I also monitor my pressure in all tires with a TPMS (PressurePro).
__________________
Chris Beierl
2005 Winnebago Vectra 36RD
|
|
|
11-20-2012, 08:07 PM
|
#6
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,704
|
I think you are still fine at 85 psi - plenty of margin to allow for side-to-side imbalance or some extra weight onboard. But nothing wrong with staying at 90 either.
Nothing says front and rear axles have to use same psi, so feel free to adjust them separately. Just make sure all the tires on one axle have the same pressure.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
11-20-2012, 09:28 PM
|
#7
|
Senior Member
Join Date: Apr 2012
Location: Louisville, KY
Posts: 1,417
|
I run at 85 psi and also run with a TPMS. This last week I had the "pleasure" of driving through the midwest just as that nasty cold front came through. Adjusted my pressures to ~90 psi at end-of-day temps and that gave 85 psi at morning cold temps (25F - brrr). Running pressures then increased to ~98 psi. Typical and consistent with previous experience. I REALLY like the peace of mind the TPMS gives....
__________________
- 2017 Newmar London Aire -
|
|
|
11-20-2012, 09:38 PM
|
#8
|
Registered User
Vintage RV Owners Club Gulf Streamers Club
Join Date: Oct 2010
Location: Indiana
Posts: 4,951
|
Quote:
Originally Posted by adehaan86
If you do drop below the recommended 90 PSI I would highly recommend TPMS. Also I think if you drop to 85 you should be fine because once tires heat up they will be above 90. However I would stay as close to 90 as you can if possible.
|
You do not worry about 'running PSI'. ALL PSI's are set 'cold'. If you try to set the PSI so it matches the charts recomedation for 'cold', you will actually be UNDERinflated.
|
|
|
11-20-2012, 09:40 PM
|
#9
|
Registered User
Vintage RV Owners Club Gulf Streamers Club
Join Date: Oct 2010
Location: Indiana
Posts: 4,951
|
Quote:
Originally Posted by Gary RVRoamer
I think you are still fine at 85 psi - plenty of margin to allow for side-to-side imbalance or some extra weight onboard. But nothing wrong with staying at 90 either.
Nothing says front and rear axles have to use same psi, so feel free to adjust them separately. Just make sure all the tires on one axle have the same pressure.
|
|
|
|
11-20-2012, 09:41 PM
|
#10
|
Registered User
Vintage RV Owners Club Gulf Streamers Club
Join Date: Oct 2010
Location: Indiana
Posts: 4,951
|
Quote:
Originally Posted by MN_Traveler
I run at 85 psi and also run with a TPMS. This last week I had the "pleasure" of driving through the midwest just as that nasty cold front came through. Adjusted my pressures to ~90 psi at end-of-day temps and that gave 85 psi at morning cold temps (25F - brrr). Running pressures then increased to ~98 psi. Typical and consistent with previous experience. I REALLY like the peace of mind the TPMS gives....
|
Again, do NOT try to adjust PSI by running temps. ALL PSI's are set 'cold'...
|
|
|
11-20-2012, 10:05 PM
|
#11
|
Senior Member
Join Date: Apr 2012
Location: Louisville, KY
Posts: 1,417
|
Let me be clear: with my weights my cold pressures (by the charts) ARE 85 psi. I simply meant that before I went to bed (with "cold" tires set at 90 psi, but not as cold as morning temps) when I verified in the morning, I hit the 85 psi cold target ( lucky guess). If I had not hit that, I would have adjusted appropriately. I ABSOLUTELY agree that you should not adjust pressures at running temps to the chart pressures: if you do you will be under inflated. Per my TPMS my running pressures are easily 15-20 (or more) psi above the cold set point. Sorry for any confusion.
__________________
- 2017 Newmar London Aire -
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|