exportman
Clovis, Ca
Senior Member
Joined: 06/29/2002
View Profile
Good Sam RV Club Member
|
Just bought new tires for the motor home, 245.70R.19.5s. The plate on the door says they should be inflated to 85psi. The tire dealer says "no" that they should be 110 psi. Isn't what is on the factory installed plate the more important consideration?
|
pulsar
Lewisville, NC
Senior Member
Joined: 12/30/2001
View Profile
Good Sam RV Club Member
|
You need to load your rig the way you would travel, weigh each wheel separately, and then use the air pressure recommended by the tire manufacturer. Most tire manufacturers will have a chart on their website.
Tom
|
pulsar
Lewisville, NC
Senior Member
Joined: 12/30/2001
View Profile
Good Sam RV Club Member
|
Moved from Forum Technical Support.
|
camperkids1025
Bel Air, MD.
Senior Member
Joined: 07/27/2005
View Profile
Good Sam RV Club Member
 Offline
|
Ideally the MH should be weighed and then go by the tire inflation chart for that brand of tires. You are correct go by the inflation on the plate. You would ride so hard @ 110 and. I run 80psi in mine and it rides good and tires ware good. Jim
The Camperkids Jim & Lois
3 Grandkids Maria, Christian, Antony (part timers)
1999 Newmar Mountain Aire 37.5ft, Ford V-10, F-53 Chassis, Bilsteins Shocks W/ Bilstein Steering Stablizer, HWH Levelers
|
accsys
Green Cove Springs, FL
Senior Member
Joined: 07/09/2006
View Profile
Good Sam RV Club Member
Offline
|
You need to go to the web site for your tire manufacturer and download the inflation chart for the size tire you have. The inflation for the tire is dependent on the weight that tire has to support. Just make sure all the tires on the same axle are inflated to the pressure requiredfor the tire supporting the most weight. Yes, this requires that you get a weight for each corner of your vehicle. In the absence of four corner weighing you could air each up to the max pressure stated on the tire sidewall but that will give you a much rougher ride than necessary.
John & Doris
Doris and Robbies Blogs
2007 Tiffin Phaeton QDH 40 w/Cat 7 350
2004 Liberty Renegade 4x4 Toad
Roadmaster Falcon 2 tow bar
Air Force One toad braking system
FMCA F380583, PA, Good Sams
|
|
|
hallock5
Texas
Senior Member
Joined: 01/30/2012
View Profile
Offline
|
And one of the big 'gotchas', check and verify speed rating of tire.
2008 Jayco Eagle Superlite 28.5RLS
2002 Ford 4x4 SuperCab 7.3 (Jr International) Diesel
Sad to say, time to sell to a good home.
|
kaydeejay
SE Michigan, USA
Senior Member
Joined: 07/26/2004
View Profile
Offline
|
exportman wrote:Just bought new tires for the motor home, 245.70R.19.5s. The plate on the door says they should be inflated to 85psi. The tire dealer says "no" that they should be 110 psi. Isn't what is on the factory installed plate the more important consideration? If they are the same size as the original tires, then the tire placard in the Moho is stating the correct pressure when loaded to GVWR. That is the LAW!
If the tires are NOT the same size as the original, then weighing and using pressure charts is the correct way to go.
The only time they should be inflated to their max pressure of 110psi is if they are carrying their max rated load.
Keith J.
1999 Sunnybrook 27RKFS Fiver.
2005 GMC Sierra 2500HD CC/SB/DA 2WD, LBZ air cleaner, 52 gal Titan tank, Bilsteins, Line-X, Westin steps, Prodigy, Retrax cover, 16K Superglide, 5th-Airborne pin-box, Multi-vex mirrors, TST TPMS.
|
louiskathy
Oregon (presently)
Senior Member
Joined: 03/23/2003
View Profile
Offline
|
I'm not an expert on anything... I'll tell you what i have learned by experience. the Mfg of the motor homes seem to want the nicest ride possible and so they want just enough air in the tire to get the motor home to ride nice (on a soft tire). So they recommend under 90.
The tire mfg. and the tire installers go by a chart. They have never ridden inside a motor home or driven one. They want the tire inflated toward the max and that gets you a hard tire with lots of jolts going down the road.
I think our MH tires are inflated to around 85 or 90. Certainly not over 100.
Maybe this will shed some light on why the sellers of the MH's and the sellers of the tires differ so much.
JMHO
Kathy
|
Klueck
Florida
Senior Member
Joined: 11/15/2008
View Profile
Offline
|
accsys wrote:You need to go to the web site for your tire manufacturer and download the inflation chart for the size tire you have. The inflation for the tire is dependent on the weight that tire has to support. Just make sure all the tires on the same axle are inflated to the pressure requiredfor the tire supporting the most weight. Yes, this requires that you get a weight for each corner of your vehicle. In the absence of four corner weighing you could air each up to the max pressure stated on the tire sidewall but that will give you a much rougher ride than necessary.
X2
but if you can't get a four corner weight, weigh each axel, and divide by two to get an estimate on each tire. Then go by the tire manufacture recommendations for the correct psi.
|
elkhornsun
Monterey
Senior Member
Joined: 11/29/2011
View Profile
Offline
|
Max pressure depends not on size but the load rating. Same size tire in a D, E, G rating will have different maximum pressures and maximum load capacity based on that pressure.
Personally when I first switched to 80 PSI E rated tires I expect the ride to be harder with them fully inflated. I use the manufacturer's chart for the tires to provide enough air for the load of the vehicle and drove them for 2000 miles. I then noticed that there was a lot more wear on the outside edges of the tires, a sure sign of under inflation. I brought the tires up to their maximum rated pressure and noticed no difference in the ride nor did my wife notice any difference. My concerns were groundless and that with a vehicle carrying a heavy load the maximum rated pressure is a good place to start.
|
|
|
