Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
 


Reply
 
Thread Tools Display Modes
 
Old 07-03-2008, 06:45 PM   #1
Senior Member
 
Join Date: Jun 2008
Location: Salinas, CA
Posts: 147
E-350 tire PSI??

2008 Ford E-350 Diesel 2X4 RB .... The door jam labels recommend 80 PSI for the rear tires and 55/60 for the front tires. Does one run the recommended pressure or a little less? When I picked it up it was 70 rear and 50 front. Getting ready for a 3-week run to Canada.

Philip
__________________

salivan is offline   Reply With Quote
Old 07-03-2008, 06:46 PM   #2
Senior Member
 
yvrr's Avatar
 
Join Date: Oct 2007
Location: Newark, CA
Posts: 795
What size and rating are the tires?
__________________

__________________
Jack
'01 Ford EB50p Quigley 4WD
yvrr is offline   Reply With Quote
Old 07-03-2008, 06:53 PM   #3
Senior Member
 
Join Date: Jun 2008
Location: Salinas, CA
Posts: 147
LT245/75R16 ... OEM from Ford "Hankook" brand (Korea)
salivan is offline   Reply With Quote
Old 07-03-2008, 07:46 PM   #4
Site Team
 
Ford_6L_E350's Avatar
 
Join Date: May 2007
Location: Washington - Ridgefield
Posts: 4,727
The factory tire pressures are based on the van being fully loaded. Either you can weigh the van to determine the weights on the front and rear or you can guess. More weight needs more pressure.

Your stock tires are rated at 3042# @ 80psi. You can derate that linearly.
38#/psi. The tires will support some weight at 0psi, but linear is close enough.

Since the rear axle has two tires, it can support 6084# at 80psi. If your rear axle weighed 4000#, it would take 52psi to support that weight.

If the van were empty and weighed 3800# front and rear you could run 50/50 for tire pressures.

An old trick was to measure the tire pressure then drive at highway speeds with the load you want to use. Then after and hour measure the hot tire pressures. If the pressure went up more than 6 psi, your pressure was too low. If the pressure went up less than 3 psi, your pressure was too high.

Mike
__________________
Alaska to Key West, Labrador and more
Prostate cancer survivor. See Thread Prostate cancer and Sportsmobiles
2015 VW GTI 2020 Fiat 124 Spider
2012 E250 Hitop camper
Ford_6L_E350 is offline   Reply With Quote
Old 07-03-2008, 10:08 PM   #5
Site Team
 
BroncoHauler's Avatar
 
Join Date: May 2007
Location: Southern New Mexico
Posts: 9,798
My driver's side door jamb has a van weight and recommended tire pressure sticker added by SMB.

Do not base the tire pressure on the maximum recommended tire pressure on the side of the tire, but of course, do not exceed that tire pressure.


Herb
__________________
SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.
BroncoHauler is offline   Reply With Quote
Old 07-07-2008, 10:01 PM   #6
Senior Member
 
Greg In Austin's Avatar
 
Join Date: Jul 2007
Location: Austin, Texas
Posts: 1,543
Send a message via AIM to Greg In Austin Send a message via Yahoo to Greg In Austin
The key to this whole thing is to check the MAX COLD PRESSURE on the sidewall of the tire. Use that and the weight of your van to determine the appropriate range of tire pressure.

Tires get changed and the door jam sticker may not.

Check the tire sidewall.

I have not even looked at the door sticker on our 2008. Our 35in E-rated tires have a max pressure of 65 or 66psi.
__________________
Greg in Austin
2008 Ford 6.0PSD EB/E-PH SMB 4X4 Aluminess f/r bumpers (13.5mpg avg, 15mpg hwy) 52k miles [Texas McBeast]
2006 Toyota Prius (48 to 68 mpg) 120k miles [Penelope]
2013 Jeep Wrangler Unlimited Rubicon (15 to 18 mpg) [Johnnie]
2012 Mitsubishi MiEV (no gas required) ($.50/day in electricity) [Evie]
https://badge.facebook.com/badge/1232...3.32047100.png
Greg In Austin is offline   Reply With Quote
Old 07-28-2008, 01:36 PM   #7
Senior Member
 
Join Date: May 2007
Location: San Diego, CA
Posts: 989
Mike, thanks for the really helpful information. Are there any advantages/disadvantages to running the tires at a higher PSI than the formula supplied in your post? My new tires are rated for 3750 lbs at 80 psi. The weights on my door jamb are 4400 lbs (front) and 6084 lbs (rear). Using the formula, it says I should be running the fronts at approximately 47 psi and the rears at 65 psi.
__________________
2007 Ford RB Diesel SMB 4x4 Pueblo Gold; Custom configuration (aisle layout); PIAA 580 driving lights; Picked up on Oct 19, 2007.
sdwindansea is offline   Reply With Quote
Old 07-28-2008, 01:48 PM   #8
Site Team
 
Ford_6L_E350's Avatar
 
Join Date: May 2007
Location: Washington - Ridgefield
Posts: 4,727
Quote:
Originally Posted by sdwindansea
Are there any advantages/disadvantages to running the tires at a higher PSI than the formula supplied in your post?
Yes, and I'm sorry I forgot to mention it.

Lower pressures generate more flex and more friction in the tire. That lowers your mileage (fuel and tire) and makes heat - heat that can damage or kill a tire (and passengers - remember the Ford/Firestone fiasco).

Higher pressures are the opposite of above. Higher pressures tend to make a harder ride, but better on road handling.

I tend to run 15% above the calculated numbers as a safety factor. But, never exceed the max ratings on the tire sidewall.

Mike
__________________

__________________
Alaska to Key West, Labrador and more
Prostate cancer survivor. See Thread Prostate cancer and Sportsmobiles
2015 VW GTI 2020 Fiat 124 Spider
2012 E250 Hitop camper
Ford_6L_E350 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

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 11:03 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×