Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-26-2012, 11:10 AM   #1
4 Rivet Member
 
Morgan guy's Avatar
 
2007 27' Classic FB
Fredericksburg , Texas
Join Date: Jun 2011
Posts: 288
Question Safe Tire Pressure

I have a 2007 AS Classic 27'. It has a GVWR of 9000 lbs. I havve 4 Maxxis load range E tires rated at a capacity of 2830 lbs/ 80 Psi, for a total load of 11,320 lbs. With an excess capacity of 2,320 lbs, I would like to run a lower air pressure than 80 lbs to give a softer ride to the trailer. Does anyone know how the pressure adjustment affects the load capacity, in other words, what can I safely lower the pressure. The label on the trailer says 65 lbs but doesn't reference what load range of tire.
__________________

__________________
Morgan guy is offline   Reply With Quote
Old 02-26-2012, 11:50 AM   #2
Rivet Master
 
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
check the tire temperature with an IR thermometer when you stop for breaks. If the tires run hot (> 140F), they need air. If they run cool (< 120F) you might get away with reducing air pressure somewhat.

The question being why you are running tires rated for much larger loads than needed while, at the same time, trying to find best ride. These two issues don't complement each other but rather contradict.

65 psi is typical D load range max sidewall rated PSI, 45 is C load range. 80 is typical for E load range.
__________________

__________________
bryanl is offline   Reply With Quote
Old 02-26-2012, 11:59 AM   #3
Rivet Master
 
A W Warn's Avatar
 
2000 25' Safari
1999 34' Excella
Davidson County, NC , Highlands County, FL
Join Date: Aug 2006
Posts: 2,573
I do not know about your wheels, but my wheels have a 65 psi max air pressure.
__________________
Alan
2014 Silverado 1500 Crew Cab 5.3L maximum trailering package (yes, I'm towing the 34')
A W Warn is offline   Reply With Quote
Old 02-26-2012, 12:03 PM   #4
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by Morgan guy View Post
I have a 2007 AS Classic 27'. It has a GVWR of 9000 lbs. I havve 4 Maxxis load range E tires rated at a capacity of 2830 lbs/ 80 Psi, for a total load of 11,320 lbs. With an excess capacity of 2,320 lbs, I would like to run a lower air pressure than 80 lbs to give a softer ride to the trailer. Does anyone know how the pressure adjustment affects the load capacity, in other words, what can I safely lower the pressure. The label on the trailer says 65 lbs but doesn't reference what load range of tire.
More than likely, when you drop the tire pressure enough so you don't beat the trailer to death, the tires will show abnormal wear.

Also, most wheels won't take 80 PSI, over a long haul, without a fracture showing up.

"D" tires provide all the safety and performance that's needed, AND, with room to spare.

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 02-26-2012, 02:35 PM   #5
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,193
Check the tire placard on your trailer. The recommended pressure should be listed there. Generally, it is 60-65 psi. Some smaller Airstreams with smaller/lower load range tires will be less.
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
overlander63 is offline   Reply With Quote
Old 02-26-2012, 02:46 PM   #6
Site Team
 
, Minnesota
Join Date: Aug 2003
Posts: 6,940
Images: 59
Here's the chart you asked for.
__________________
markdoane is offline   Reply With Quote
Old 02-26-2012, 02:46 PM   #7
kds
3 Rivet Member
 
2008 27' Safari FB SE
Frederickburg , Texas
Join Date: Apr 2008
Posts: 186
Quote:
Originally Posted by Inland RV Center, In View Post
More than likely, when you drop the tire pressure enough so you don't beat the trailer to death, the tires will show abnormal wear.

Also, most wheels won't take 80 PSI, over a long haul, without a fracture showing up.

"D" tires provide all the safety and performance that's needed, AND, with room to spare.

Andy
So are there any disadvantages to buying a load E tire? I have 4 year old GM on my trailer now and will be replacing this month. My GW is 7600 and my tire guy advised me to go to a an E rated tire. Any idea why he would recommend this? I thought it would just be for extra safety. He recommended Greenball tires.

Kelly
__________________
kds is offline   Reply With Quote
Old 02-26-2012, 03:35 PM   #8
Lost in America
 
mojo's Avatar
 
2015 27' FB International
2006 25' Safari FB SE
2004 19' International CCD
Oak Creek , Arizona
Join Date: Feb 2007
Posts: 1,507
Inflation

  • Always inflate trailer tires to the maximum inflation indicated on the sidewall.
  • Check inflation when the tires are cool and have not been exposed to the sun.
  • If the tires are hot to the touch from operation, add three psi to the max inflation.
  • Underinflation is the number one cause of trailer tire failure.
Load Carrying Capacity

  • All tires must be identical in size for the tires to properly manage the weight of the trailer.
  • The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
  • The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
  • If the actual weight is not available, use the trailer GVW. If a tire fails on a tandem axle trailer, you should replace both tires on that side. The remaining tire is likely to have been subjected to excessive loading.
  • If the tires are replaced with tires of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.
__________________
This is the strangest life I've ever known - J. Morrison

The Nest Egg - 2015 Airstream International Serenity 27FB
2017 Silverado 2500HD Chevy Duramax Diesel

mojo is online now   Reply With Quote
Old 02-26-2012, 03:58 PM   #9
Rivet Master
 
2005 19' Safari
GLENDALE , AZ
Join Date: Aug 2004
Posts: 2,441
Just a comment, but the tire temperatures mentioned above may be inaccurate, depending on your location. In Arizona, the "cool" running temperature of 120-degrees or less doesn't apply year-round; as in the summer, tires can measure this or higher when standing in the sun, even before your Airstream hits the street.

We verify 80 psi in trailer tires in the evening or early morning before leaving on trips, then don't worry about specific tire temperatures on the road. I have an infrared thermometer and check the tires at fuel and rest stops, but that is more to verify that they are still approximately the same temperature in comparison to the reading at the previous stop, rather than to verify a specific temperature range.

The Airstream tires usually measure approximately the same temperature as the tires on our tow vehicle, although the rear tires on our pickup are usually 5-10 degrees hotter because they are the drive wheels and we usually have a lot of stuff in the bed.

Note: We run load range E tires at 80 psi, because our single axle Bambi has a higher tire load (i.e., more weight per tire) than larger models with multiple axles.
__________________
Phoenix is offline   Reply With Quote
Old 02-26-2012, 04:19 PM   #10
Rivet Master
 
Ray Eklund's Avatar

 
2014 25' International
2006 23' Safari SE
Currently Looking...
Boulder City , Nevada
Join Date: Aug 2007
Posts: 2,369
Tire Pressures for AS

Mojo. I am with you... aren't I?

I was blessed with the AS wheel size of 14" and 50 pounds maximum. The four factory Goodyears fell apart the first year. Punctures through the tread, blowouts. When I brought the 23 footer home I noticed bubbles in the outside smooth surface. The friendly Goodyear dealer said I must have done something to them and stiffed me good for a replacement. Good bye Goodyear.

I bought 5 TowMax Power King 14 inch tires. ALWAYS inflate them to the maximum of 50 pounds. I do not drive any differently... NEVER had a problem since. My solution to the 14 inch C rated tire and 14" wheels is getting 15 inch wheels and D rated tires. I will probably AVOID trailer rated tires and use a Michelin street tire. As some has said in some older thread... you will die and be sued for using non trailer tires on your AS. I think they have it wrong. I will die and kill others USING trailer rated tires. I will wait until there is some rating tests done to fix the problem with trailer rated tires.

Inflate your tires and your AS will pop its rivets??? Inflate your tires and your AS will fall apart and be a parts trailer. The screws in the cabinets will fall out of your AS once you drive off of the dealer's lot. Drawers coming off their hinges. Plumbing coming loose. Must be tire pressure related? Now that I have "upgraded" my hinges and hardware I have virtually nothing falling off.

I had trusted the judgment of some professionals on the Forum, but now have had to try out my own ideas. Things have improved for my back country uses for trailer and tow vehicle since I started using common sense.

My Tundra 2008 came with Goodrich, C rated mud and snow tires and a street Michelin spare on a steel wheel. They did not last with tire punctures through the tread and excessive wearing. I bought five of the Michelin E rated tires from Costco, Nitrogen used for "air", inflated to 48psi when mounted at Costco. I have not needed to add Nitrogen since I bought the tire set. They have never given me one problem. My Tundra is at 63,000 miles and has not shaken apart, exploded on the highway or had another tire problem. They are tough to balance, because there is tire rubber on these tires. They are also a bit expensive to swallow... but you will not regret it.

This dialogue I have not edited or prewritten with all of the fine details, miles driven and when tire failures occurred. Why do you think Toyota and AS put the tires on their products... because they are the best or they are cheap and will do, getting you off the lot.

We spend months traveling the back roads. Gravel, rock, dirt, mud, snow, slop and anything in between. I drive like the guy who is flying you on the Jumbo Jet to Australia. I want my truck, my AS, my tires, my water filter, AS faucets replaced with something that is good, etc. Never killed anyone. Never hit a Moose on a mountain road. Never had the aluminum pop off the frame and kill a baby chipmunk on the side of the road. I am sure there are some who will criticize the messenger and I am use to that. My trailer and truck NEED to handle the loads and roads I use in the back country. My methods ARE REAL.

I am saying. Listen to the advice some of these people are giving to you and then think about it some more. Common sense may save your life.

My friend bought a 2012 Tundra. The Goodrich tires are the same as my 2006's. He was told NOT to inflate the tires to the max when towing as it would ruin the suspension... What!? The commercials show them hauling a ton of rock around... Watch out for the advice that just might be untested. My advice IS tested and I sometimes just get cranky when I hear some of this mumbo jumbo. If my trailer pops rivets, I tell it like it is on the Forum. Folks... Buy M. F. Global stock... they know how to treat their customers... right... don't they.?
__________________
Ray Eklund is offline   Reply With Quote
Old 02-26-2012, 06:11 PM   #11
Rivet Master
 
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
re: "I do not know about your wheels, but my wheels have a 65 psi max air pressure." -- very good point. Wheels have ratings like tires do and those ratings do need respect.

re: "Just a comment, but the tire temperatures mentioned above may be inaccurate, depending on your location. In Arizona, the "cool" running temperature of 120-degrees or less" -- The tire temperatures are reasonably accurate as a rule of thumb. When tires start running at over 140F, the failure rate goes up. This is also related to the speed rating for the tire. If running in hot desert conditions or at high speeds, increase the tire pressure or reduce the speed (or both) to keep tire temperatures at safe levels. There's a lot of issues on this but the fact is that the stuff tires are made of don't like very high temperatures.

Tire temperature is a primary indicator of how the tire is handling its weight load for the speeds being travelled. It is easy to measure on a walkaround and that makes it a good thing to do to keep an eye out for potential tire problems. This is also why temperature is one of the measures available on the better TPMS. -- check it yourself and get your own range of operating tire temperatures that you can use to detect anomalies or potential problems.

re: "the tires will show abnormal wear." -- this is the traditional test for proper tire inflation but most TT tires are replaced due to age and not wear. A bit of extra wear in the center of the tread won't be noticeable unless you put a lot of miles on the trailer every year. That is why many recommend running tires at max sidewall rating rather than try to finagle weight charts and such things as underinflation risks are much more significant than wear risks (usual caveats apply for those seeking to find fault or whatnot)

What with the Airstream suspension, tires aren't usually the major issue for vibration and related problems. The hitch appears to be a more likely suspect on this.

re: "my tire guy advised me to go to a an E rated tire. Any idea why he would recommend this?" -- a lot of times a bit of extra capability can be a good thing, a safety margin. For TT tires, that doesn't seem to be the case.

re: "Watch out for the advice that just might be untested." -- very good advice, I think, but one also has to be careful to evaluate the method of testing. There is a lot of anecdotal 'testing' that doesn't include a decent sample size or account for the many variables often involved in the real world. This is why getting a basic understanding of the underlying technology can be a necessary means to qualify what one hears. Knowing the why and how can help you adapt the experience of others to your own circumstances.
__________________
bryanl is offline   Reply With Quote
Old 02-26-2012, 07:44 PM   #12
Vintage Kin
 
slowmover's Avatar
 
Fort Worth , Texas
Join Date: Nov 2006
Posts: 7,603
Images: 1
TT tires need to be at maxmum sidewall pressure.

As Andy indicates, one must spec a tire of the proper load range (12-15% reserve capacity; what is trailer scaled weight?). Tire rim width must be a close match to tread width. An open shoulder traction tread is not ideal, but closed shoulder, etc.

No one is happy with ST tires, deservedly so, thus upsizing to a larger rim (16 or 17") and spec'ng an LT tire of the proper load factor takes more work.

Tire temps can vary in as much as .5 inch. And surface temps are not indicative of what's happening within for given accuracy. Nor do TPMS with valve stem adaptors give "true" temps. Etc. Almost WAG.

But moving to "E" tends to be too much, ideally.

In short, it's hard to get away from ST ( appears they suffer from lack of technological development the past dozen years), but it still appears to be worth the effort.

Individual wheel weights (not just axle average) is best information for starting.

.
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 9-cpm solo, 15-cpm towing
Sold: Silver Streak Model 3411
slowmover is offline   Reply With Quote
Old 02-26-2012, 07:51 PM   #13
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,410
Images: 5
Quote:
Originally Posted by REDNAX View Post
TT tires need to be at maxmum sidewall pressure.

As Andy indicates, one must spec a tire of the proper load range (12-15% reserve capacity; what is trailer scaled weight?). Tire rim width must be a close match to tread width. An open shoulder traction tread is not ideal, but closed shoulder, etc.

No one is happy with ST tires, deservedly so, thus upsizing to a larger rim (16 or 17") and spec'ng an LT tire of the proper load factor takes more work.

Tire temps can vary in as much as .5 inch. And surface temps are not indicative of what's happening within for given accuracy. Nor do TPMS with valve stem adaptors give "true" temps. Etc. Almost WAG.

But moving to "E" tends to be too much, ideally.

In short, it's hard to get away from ST ( appears they suffer from lack of technological development the past dozen years), but it still appears to be worth the effort.

Individual wheel weights (not just axle average) is best information for starting.

.
This is all accurate and true...however, one can, through observation, note the "normal" PRESSURE changes while solo traveling over time with TPMS on the TV and draw valid conclusions on what is going on with trailer TPMS PRESSURES. While not a scientific numerically accurate judgement of interior tire surface temp...it's pretty indicative of impending issues of enough significance to predict a potential issue. Pay attention and draw your own conclusions.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 02-26-2012, 11:01 PM   #14
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by kds View Post
So are there any disadvantages to buying a load E tire? I have 4 year old GM on my trailer now and will be replacing this month. My GW is 7600 and my tire guy advised me to go to a an E rated tire. Any idea why he would recommend this? I thought it would just be for extra safety. He recommended Greenball tires.

Kelly
Kelly.

Your tire guy might be great for cars and trucks, but he obviously knows very little about an Airstream.

Oh, one more thing, he knows how to dig in a persons pocket, too.

Ask him what is the principle method of construction of an Airstream. I'll bet he doesn't have a clue.

Andy
__________________

__________________
Inland RV Center, In is offline   Reply With Quote
Reply


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
Safe Tire Pressure Morgan guy Tires 165 01-10-2013 01:49 PM
02/12: New Tire Discussion on Woodalls: LT versus ST and more. slowmover Tires 128 04-10-2012 06:09 PM
Putting a safe in 2012 27' FB Int Jordanparson General Interior Topics 5 02-24-2012 11:33 PM
Bolt pattern & tire size for 68' Ambassador silverwoman Wheels, Hubs & Bearings 3 02-16-2012 10:36 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:30 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.