Reply
 
Thread Tools Display Modes
Old 07-23-2015, 03:48 PM   #1
Senior Member
 
thestrangebrew's Avatar
 
Join Date: Apr 2014
Posts: 373
Question about "cold" psi

Getting ready to head out in about 2 hrs and I'm second guessing myself for this trip. My max rated psi is 50 psi "cold" on my Roo. I didn't get a chance to check the pressure until about 11am, outside temp at that time was around mid 80s. Pressure at that time was around 45psi in each tire. Since it's supposed to be 50 psi "cold", in mid 80s temp, is ~48 psi ok or is that too much given outside temps? Hoping for a quick response and TIA!
__________________
2014 F-150 SCREW Ecoboost 4x4.

2014 Rockwood Roo 233s
thestrangebrew is online now   Reply With Quote
Old 07-23-2015, 03:51 PM   #2
Phat Phrog Stunt Team
 
TURBS's Avatar
 
Join Date: Aug 2011
Location: Iowa
Posts: 34,498
Cold meaning the tire is not hot from travel.

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "15 nights"
TURBS is offline   Reply With Quote
Old 07-23-2015, 03:52 PM   #3
Phat Phrog Stunt Team
 
TURBS's Avatar
 
Join Date: Aug 2011
Location: Iowa
Posts: 34,498
Fill it to 50 and go camping!

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "15 nights"
TURBS is offline   Reply With Quote
Old 07-23-2015, 03:54 PM   #4
Site Team
 
wmtire's Avatar
 
Join Date: Nov 2010
Location: Northeast Louisiana
Posts: 24,066
Quote:
Originally Posted by thestrangebrew View Post
Getting ready to head out in about 2 hrs and I'm second guessing myself for this trip. My max rated psi is 50 psi "cold" on my Roo. I didn't get a chance to check the pressure until about 11am, outside temp at that time was around mid 80s. Pressure at that time was around 45psi in each tire. Since it's supposed to be 50 psi "cold", in mid 80s temp, is ~48 psi ok or is that too much given outside temps? Hoping for a quick response and TIA!
it sounds like you are low, not high. Air expands as it get's hotter. Your 11 am pressure would be higher than your 7 am pressure, since the ambient air temp is hotter. If it was 45psi at 11 am, then it was probably 43-44 psi at 7 am.

You want at least 50 psi in your tire currently, and tomorrow morning it may be down to 48 so you can air it up again.

As you have it now, you are less than 50, and tomorrow morning will be even lower than it is now.
__________________
2011 Flagstaff 831 RLBSS

I'm trying to keep up with the Joneses, but every time I catch up, they refinance.
wmtire is online now   Reply With Quote
Old 07-23-2015, 03:56 PM   #5
Senior Member
 
thestrangebrew's Avatar
 
Join Date: Apr 2014
Posts: 373
Great thanks guys! I'll fill 'em up and wait. And wait. And wait. For the DW to pack her stuff lol.
__________________
2014 F-150 SCREW Ecoboost 4x4.

2014 Rockwood Roo 233s
thestrangebrew is online now   Reply With Quote
Old 07-23-2015, 03:57 PM   #6
Phat Phrog Stunt Team
 
TURBS's Avatar
 
Join Date: Aug 2011
Location: Iowa
Posts: 34,498
Quote:
Originally Posted by thestrangebrew View Post
Great thanks guys! I'll fill 'em up and wait. And wait. And wait. For the DW to pack her stuff lol.
Always waiting on the dw.


TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "15 nights"
TURBS is offline   Reply With Quote
Old 07-23-2015, 04:01 PM   #7
Senior Member
 
mcnabbwr's Avatar
 
Join Date: Mar 2014
Location: Lower Michigan
Posts: 1,465
Quote:
Originally Posted by TURBS View Post
Always waiting on the dw.


TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "15 nights"
Sounds about right!
__________________
Bill & Pam
2014 Trilogy 3650RE
2015 F350 PSD
mcnabbwr is offline   Reply With Quote
Old 07-23-2015, 04:18 PM   #8
Senior Member
 
schrederman's Avatar
 
Join Date: Apr 2012
Location: Weatherford, TX
Posts: 977
The word "cold" should actually translated to ambient. Summer temps here in the early morning are about 80 degrees... If I go on a trip in summer, I start with my tires at max sidewall pressure that morning at 80. In winter, it may be 42... So, if I go on a trip in winter, again, it's max sidewall pressure at 42. Don't read too much into it...
__________________
J & D in Lovely Weatherford, TX
2016 Jayco White Hawk 28DSBH TT
2014 Ram 2500 Crew Cab 4X4 6.7L Cummins
schrederman is offline   Reply With Quote
Old 07-23-2015, 04:41 PM   #9
Senior Member
 
accumack's Avatar
 
Join Date: Sep 2011
Posts: 522
Do not exceed the maximum pressure (cold) it is that maximum.
accumack is offline   Reply With Quote
Old 07-23-2015, 06:23 PM   #10
Anacortesians
 
Join Date: Oct 2010
Location: Anacortes, WA
Posts: 1,166
Usually the max pressure molded into the sidewall is much too high for a comfortable ride. The best way to get it correct would be to drive onto a weighbridge just leaving the axle you want to inflate on the scale. Divide the load the scale shows by the number of tires supporting the weight then inflate to the tire manufacturer's recommended pressure for that load.
__________________
Frank and Eileen
No longer RVers or FR owners
F and E Damp is offline   Reply With Quote
Old 07-23-2015, 06:36 PM   #11
Senior Member
 
Join Date: Jul 2010
Location: Waynesville
Posts: 14,207
Quote:
Originally Posted by F and E Damp View Post
Usually the max pressure molded into the sidewall is much too high for a comfortable ride. The best way to get it correct would be to drive onto a weighbridge just leaving the axle you want to inflate on the scale. Divide the load the scale shows by the number of tires supporting the weight then inflate to the tire manufacturer's recommended pressure for that load.
I am going to take Turbs advice and put (50#) in the Tires and Hit the ROAD!! Youroo!!
youroo is offline   Reply With Quote
Old 07-23-2015, 06:56 PM   #12
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,705
Quote:
Originally Posted by F and E Damp View Post
Usually the max pressure molded into the sidewall is much too high for a comfortable ride. The best way to get it correct would be to drive onto a weighbridge just leaving the axle you want to inflate on the scale. Divide the load the scale shows by the number of tires supporting the weight then inflate to the tire manufacturer's recommended pressure for that load.
Nobody is riding in the trailer and the tires need to be inflated to max cold (ambient) pressure. Why make things soooooo complicated????
__________________
OldCoot is offline   Reply With Quote
Old 07-23-2015, 07:05 PM   #13
Fulltime family RVer
 
ependydad's Avatar
 
Join Date: Nov 2011
Posts: 19,905
Quote:
Originally Posted by OldCoot View Post
Nobody is riding in the trailer and the tires need to be inflated to max cold (ambient) pressure. Why make things soooooo complicated????

Why do tire manufacturers publish load inflation tables????
__________________
2018 Ram 3500 DRW/crew cab/long bed/4x4/4.10 gears pulling a 2017 Spartan 1245 by Prime Time
Checkout my site for RVing tips, tricks, and info | My family and I have fulltimed since June 2015
ependydad is offline   Reply With Quote
Old 07-23-2015, 07:12 PM   #14
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,705
Quote:
Originally Posted by ependydad View Post
Why do tire manufacturers publish load inflation tables????
So people have something to read?

If he is on C rated tires, he is close to the load limit anyway. Why complicate things as I said before. There are other things to do besides driving over a scale every time you add X# to a camper. JMO
__________________
OldCoot is offline   Reply With Quote
Old 07-24-2015, 10:40 AM   #15
Senior Member
 
panthercity's Avatar
 
Join Date: Jun 2015
Posts: 213
Quote:
Originally Posted by TURBS View Post
Always waiting on the dw.


TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "15 nights"
https://youtu.be/M-C-IbkuNWs
__________________
Certified JB Welder. Certified 3M Duct Tape installer.
Certified Farmer's Co-Op bailing wire expert. Graduate of the "Rock on the side of the Trail as a Hammer" school of motorcycle repair.
Getting old is just a matter of narrowly missing all the things that kill you.
panthercity is offline   Reply With Quote
Old 07-24-2015, 10:44 AM   #16
Senior Member
 
panthercity's Avatar
 
Join Date: Jun 2015
Posts: 213
For decades I've gone by the "2" rule: Cold tire pressure checked if they have been less than two miles or it's been 2 hours since they were run.

Had a nice hand-held interferometer for checking tire heat coming off the track back in my motorcycle roadracing days. We then adjusted pressure accordingly.
__________________
Certified JB Welder. Certified 3M Duct Tape installer.
Certified Farmer's Co-Op bailing wire expert. Graduate of the "Rock on the side of the Trail as a Hammer" school of motorcycle repair.
Getting old is just a matter of narrowly missing all the things that kill you.
panthercity is offline   Reply With Quote
Old 07-24-2015, 11:02 AM   #17
Anacortesians
 
Join Date: Oct 2010
Location: Anacortes, WA
Posts: 1,166
I certainly wasn't suggesting "every time you go out", just once a year or so, maybe, with the rig at a typical loading. I've always regarded that maximum molded into the sidewall to be a "do not exceed" number, not an every-day working pressure. Running the tires at that pressure results in wearing out the middle of the tread, because all the tread isn't touching the pavement.
__________________
Frank and Eileen
No longer RVers or FR owners
F and E Damp is offline   Reply With Quote
Old 07-24-2015, 11:09 AM   #18
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,705
Quote:
Originally Posted by F and E Damp View Post
I certainly wasn't suggesting "every time you go out", just once a year or so, maybe, with the rig at a typical loading. I've always regarded that maximum molded into the sidewall to be a "do not exceed" number, not an every-day working pressure. Running the tires at that pressure results in wearing out the middle of the tread, because all the tread isn't touching the pavement.
Have run all my trailer tires at MCP for many years and have never worn out a set of tires in the center or the edges, they usually "age" out first other than the one "china bomb" that blew and the set that wasn't balanced that scalloped and went with the trailer when we traded.
__________________
OldCoot is offline   Reply With Quote
Old 07-24-2015, 01:49 PM   #19
Senior Member
 
Join Date: Dec 2014
Location: oakdale, ca
Posts: 290
You can never get the tires at exact psi due to temps weather sun no sun. The tire manufactures label saying cold is at the time you are checking with out any driving being done on the tires yet. As you drive your pressures go up and down due to the same reasons listed above. So don't worry about rechecking in the early morning there is no exact time of the day to check.
j free is offline   Reply With Quote
Old 07-25-2015, 08:34 AM   #20
Member
 
Join Date: Apr 2015
Posts: 58
The tire company I worked for described a cold tire as one that had been sitting still for 8 hours or more or had not been driven for more than a mile before checking pressure. Do not be concerned with ambient (outside) temperature. Pressure differential, whether you check tires in the morning or the afternoon, will be negligible.
Tireguy397 is offline   Reply With Quote
Reply

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 07:08 PM.