Tire PSI - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by Kip, this thread has received 6 replies and been viewed 1820 times.

 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 06-18-2010, 05:05 AM Thread Starter
Kip
In the passing lane
 
Kip's Avatar
 
Join Date: Dec 2008
Posts: 1,453
Points: 48,495
Thanks: 56
Thanked 77 Times in 67 Posts
Tire PSI

Ok what is the max PSI for 315/75/15D tires? everything I can find on the interent says 65psi but the sidewall says 50psi. So I have been running 50psi but if I can run 65psi pulling the trailer I will.

2005 2500HD DIRTYMAX 6in lift, dual exhaust, afe airbox. Tuner soon to come

2001 PSD shortbed crewcab, ATS tranny edge juice w/attitude, Superchips programmer, Gauges, exhaust, 4inch lift w/35s, (SOLD)

Originally Posted by sledneck57
Your sweating like a queer holding a hot dog.lol.
Kip is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 06-18-2010, 10:23 AM
Senior Member
 
plainredtruck's Avatar
 
Join Date: Dec 2008
Location: Hickory Tavern, SC
Posts: 4,090
Points: 30,360
Thanks: 275
Thanked 444 Times in 285 Posts
Images: 11
Never exceed the PSI stamped on the wall.

If in doubt, don't. Then call the mfg's Customer Service #

prt

'99 F250 X-cab 2wd

powered by DP-Tuner

My Photography addiction


Mafia # 27






plainredtruck is offline  
post #3 of 7 (permalink) Old 06-18-2010, 12:24 PM Thread Starter
Kip
In the passing lane
Threadstarter
 
Kip's Avatar
 
Join Date: Dec 2008
Posts: 1,453
Points: 48,495
Thanks: 56
Thanked 77 Times in 67 Posts
thanks thats all I needed to know

2005 2500HD DIRTYMAX 6in lift, dual exhaust, afe airbox. Tuner soon to come

2001 PSD shortbed crewcab, ATS tranny edge juice w/attitude, Superchips programmer, Gauges, exhaust, 4inch lift w/35s, (SOLD)

Originally Posted by sledneck57
Your sweating like a queer holding a hot dog.lol.
Kip is offline  
post #4 of 7 (permalink) Old 06-19-2010, 05:16 PM
Super Moderator
 
John_G's Avatar
 
Join Date: Dec 2008
Location: Tyler, TX
Posts: 4,247
Points: 74,706
Thanks: 101
Thanked 407 Times in 347 Posts
PRT is correct.

There is no industry standard inflation pressure based on Load Range, some manufacturers are lower than others in the same LR.

No matter what, you want to be SURE that the tire is correctly inflated. 50 PSI on your tires might actually be significantly more than required based on the loads.

The ONLY way to know FOR SURE what inflation pressure you need is to consult the TIRE manufacturers "load inflation chart", if you can find it.

'93 F-250 HD, 7.3L IDI, 5spd - FARM TRUCK
I Support: Trailer brakes an every axle over the towing vehicle's GVW; CDLs for RVers; Safety inspections for ALL vehicles and 6 axle trucks (97K GVW proposal).

Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote - Benjamin Franklin

I vote for LIBERTY!
John_G is offline  
post #5 of 7 (permalink) Old 06-20-2010, 05:56 AM
Senior Member
 
Join Date: Mar 2007
Posts: 1,836
Points: 19,208
Thanks: 69
Thanked 134 Times in 130 Posts
The rubber manufactures tire book from many years back allowed +10% for smooth interstate runs. That would be 55# - about the same as the tolerances on gauges.

The correct pressure can be found with chalk - make a stripe across the tread in a large parking lot and roll forward until part of it wears off. If it is the center drop the pressure a couple #, if the edges add 5# and do it again. When it wears off evenly you are within a couple of # of the correct pressure, if it is more than 10% less than the sidwall get the minimum pressure from the tire manufacture. Tires rated D and heavier are subject to 'zipper' failure, that is a very smooth break at the sidewall and tread joint about a foot long. A sudden let down at 80 in the hammer lane is not real entertainment. It also comes from overloading with one dual low on air.

One thing is always acceptable is the pressure on the sidewall.

93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd
keydl is offline  
post #6 of 7 (permalink) Old 06-29-2010, 02:36 AM
Member
 
Join Date: Dec 2008
Location: Florida
Posts: 236
Points: 22,621
Thanks: 15
Thanked 30 Times in 28 Posts
so far all that i have had fail were under inflated, ran hot, and sidewall failed. Too much PSI can cause the same problem but is less apt to happen than under inflated / over loaded. As John said stick to the PSI / Load chart from the manufacturer and if you are going to error do it on the high side. Keep in mind wheels have a max PSI also. I run a 235/85 16 tire that calls for 110 psi at max load. That is 10 psi more than the wheels are rated for. A wheel failure wouldn't be pretty either. Keep in mind all inflation pressures are at a specific air temp and would have to be adjusted up or down based on true tire temp.

'93 IH 4700, 250HP DT466, L10 Cummins intercooler, 6+1, air ride.

Case 580 Super E
Galion 503 A
Cat D8H
JD A, B, MT, 40T (x2), 80, 720
Oliver 60
IH A, H, M(V8), 354, 444
johndear720 is offline  
post #7 of 7 (permalink) Old 06-29-2010, 05:40 PM
Senior Member
 
Join Date: Mar 2007
Posts: 1,836
Points: 19,208
Thanks: 69
Thanked 134 Times in 130 Posts
Do NOT adjust tire pressure based on increased pressure from temperature caused from running.

If attention to detail is your thing there is ambient temperature correction IIRC about 1 # for 10 F, so checking the tires at 80 F before a storm blows through and drops the temp to 0 F would change the tire pressure by -8 #.

The loss of 1 to 3 # pressure a month is normal so about 90% of the tires on the road are underinflated and almost all will have been run underinflated before the tread is worn out.

93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd
keydl is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
correct tire pressure for 37x13.50x20 toyo tire skter97 General Ford Truck and Excursion 15 11-02-2009 06:25 PM
Tire ? 96cummins1987 5.9L Cummins 12 Valve (1994-1998.5) 8 01-31-2009 08:54 PM
need tire help SSpeeDEMONSS The Parking Lot 7 12-24-2008 04:01 PM
Tire Rub powerstroke2003 General Ford Truck and Excursion 2 12-28-2007 12:50 AM
tire rub ? firecat General Ford Truck and Excursion 5 09-23-2007 02:55 AM

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome