|
|
10-20-2019, 02:14 PM
|
#1
|
Senior Member
Join Date: Aug 2019
Posts: 141
|
Tire pressure..Again!!!!!!
2019 Discovery. Michelin xline energy Z. Im exactly 5,600lbs on both front tire weights and exactly 10,100lbs on both back duallys. Chart says i can run 90psi on all 6 tires. Seems alittle low for me. I got them all at about 107-110 well below the 120psi max for the tires. What does everyone think?
|
|
|
|
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!
|
10-20-2019, 02:25 PM
|
#2
|
Senior Member
Join Date: May 2013
Location: Ontario, California
Posts: 2,429
|
Your tire chart was prepared by tire engineers who conducted numerous tests before publishing the info and are probably very accurate.
If you weighed your coach when it was full (black, gray, water, fuel, food, clothes, pots/pans/dishes etc, people any trinkets you take with you etc) then the posted weight and PSI charts are correct.
__________________
[SIGPIC][/SIGPIC]2016 Newmar Dutch Star 4369
Newmar Owners Club
USAF 1966-1969,- Law Enforcement 1969 - 2003, Retired since March 2003
|
|
|
10-20-2019, 02:30 PM
|
#3
|
Senior Member
Damon Owners Club
Join Date: Jul 2010
Location: Annapolis,MD
Posts: 1,458
|
Post #2 is spot on, I run my fronts at 87 and rears at 102,
based on accurate weight from scale, and I added 5 pounds
as a cushion.
Over inflated tires cause poor tire wear and a harsh ride.
|
|
|
10-20-2019, 02:41 PM
|
#4
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,678
|
I run the 90 psi from the chart, plus an extra 5 psi because I don't want to fiddle with tire pressures every day. Or even every week or two.
Why do you think you know more about the appropriate pressure than the tire engineers who built the chart?
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
10-20-2019, 05:49 PM
|
#5
|
Member
Winnebago Owners Club
Join Date: Aug 2013
Location: Brownsburg, IN
Posts: 40
|
I set mine by the manufacturers specifications. I have a 2004 Winnebago Sightseer and it calls for 80 psi all around and that is what I use. The tire spec does not know what the tire is being used on, it just tells you what the max pressure for that tire is without regard for the application.
__________________
Bob & Linda
VFW, AmLegion, NRA
2004 Winnebago Sightseer 35N
|
|
|
10-20-2019, 07:31 PM
|
#6
|
Senior Member
Winnebago Owners Club Fleetwood Owners Club Holiday Rambler Owners Club
Join Date: Dec 2011
Location: North East Florida
Posts: 2,024
|
If it were my coach and the pressure chart says 90 psi I would run 100 just for a little Cush.
__________________
2019 Horizon 42Q
Cummins L-9 450 HP
Maxum Chassis / IFS with Tag
|
|
|
10-20-2019, 07:53 PM
|
#7
|
Senior Member
Join Date: Apr 2010
Posts: 661
|
I run 10 over what the chart recommended MINIMUM pressure is. Then if I have one that slowly loses air, I have plenty of time to correct before damage is done. Here's what Goodyear has to say on their RV tire website: "When minimum inflation pressure requirements are not met, tire durability and optimum operating conditions are compromised. Tire inflation pressure should always meet at least (my emphasis) the minimum guidelines for vehicle weight." Their charts are to be considered minimum pressure recommendations as tested by their experts. They also warn against overinflation, over the tires psi rating or over the rim psi rating. If you are between those numbers, you're golden!
|
|
|
10-21-2019, 07:44 AM
|
#8
|
Senior Member
Join Date: Aug 2019
Posts: 141
|
Got it. Is 100psi too much then. Juat as a cushion?
|
|
|
10-21-2019, 08:18 AM
|
#9
|
Senior Member
Join Date: Apr 2012
Location: Louisville, KY
Posts: 1,416
|
Cushion i guess is relative to an extent i guess. I have a similar coach (Expedition). My weights versus the charts put me at the absolute minimum inflation of 85 psi (that is regardless of weights thetires should never see a lower pressure). Like an earlier poster, i run mine at 5 psi over (ie 90 psi), because that seems to mostly compensate for pressure variation due to early morning temperatures. I most definitely see a reduction in handling/ride at higher pressures, so i keep them as close as possible to that load curve rating.
(Aside, early on i ran the tires at the sidewall rating of 120. Handling was TERRIBLE)
__________________
- 2017 Newmar London Aire -
|
|
|
10-21-2019, 09:24 AM
|
#10
|
Senior Member
Join Date: Aug 2016
Posts: 3,400
|
We have a different coach than you but same principal at work. Our manufacturer charts call for 80psi Cold inflation for our weight. I run 88psi all the way around to compensate for temp variance and a little cushion. I also look at my tire wear pattern every couple of thousand miles or so to check for even wear.
BTW...I set my TPMS low alarm @ 80psi.
If you or anybody is interested, here's a great link to just about any tire question you may have.
http://www.rvtiresafety.net
|
|
|
10-21-2019, 09:24 AM
|
#11
|
Senior Member
Join Date: May 2013
Location: Ontario, California
Posts: 2,429
|
100 is fine but again, make absolutely sure your fully loaded weights correspond to the weight chart.
__________________
[SIGPIC][/SIGPIC]2016 Newmar Dutch Star 4369
Newmar Owners Club
USAF 1966-1969,- Law Enforcement 1969 - 2003, Retired since March 2003
|
|
|
10-21-2019, 10:27 AM
|
#12
|
Senior Member
Join Date: Jul 2010
Posts: 5,332
|
Quote:
Originally Posted by Gary RVRoamer
I
Why do you think you know more about the appropriate pressure than the tire engineers who built the chart?
|
I know I don’t know more than Goodyear so I asked them. Background: The psi from the placard says 92 which has no correlation to published axle weights. Ford manual says for my chassis to run 95 as I have the 7,500lb front axle. I weighed my unit and looked those weights up in the Goodyear tire chart which allows low to mid 80’s.
I emailed Goodyear about the discrepancies and the response they provided strongly suggested I use the placard weight as the minimum, and also stated that they have seen the best overall performance for my chassis is attained at 95 psi.
I fully understand why people can get so confused...
__________________
Tom
2016 Newmar Bay Star Sport 3004
2021 Jeep Gladiator Sport Willys
|
|
|
10-21-2019, 10:40 AM
|
#13
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,678
|
The placard is provided by the coach builder per federal law. Since they don't know what your coach really weighs, they have to assume worse case (loaded to axle max) and set psi accordingly.
There is no "discrepancy" - just a different perspective being presented. The Goodyear chart gives the minimum pressure required for the stated load-weight. It's the same chart the coach builder used to determine the psi for the placard. GY won't "recommend" that you use any particular value - it's up to you to choose the weight range that matches your actual loading. The coach builder assumed some weights to be used and looked up the psi in the GY table. You have actual weights, so came out at a different entry in the chart.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
10-21-2019, 10:28 PM
|
#14
|
Senior Member
Monaco Owners Club
Join Date: Jul 2018
Location: Elizabethtown, Ontario
Posts: 224
|
I find that the different tire makers, the chassis makers and all other charts to be so confusing you can't get a positive answer.
When I was investigating what psi to run my tires at, the advise ranged from 80 to 115.
I weighed front & back tires with what I considered to be the maximum just to be safe.
It was so confusing I took the average and went with it; 110 on front & 100 on rear.
Oddly thing was when I had to have a mobile tire service man come to fix a slow leak in a valve stem, he said he always puts in 100 psi no matter the size or weight of an RV. He said if I wanted to alter it, that was up to me and when I asked for some advice, he would stick to his 100 psi and said that he believed any alteration in tire pressure deteriorated the strength of the tire.
He also said he had been in the business for over 30 years......hmmmmmmm
__________________
40 foot 2002 Monaco Diplomat
2005 Ford Focus to tow around
|
|
|
|
|
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 |
|
|
|
|
|
|
|
|
|
|
|
|
|