Terrible fuel mileage - PowerStrokeNation : Ford Powerstroke Diesel Forum
 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 05-19-2019, 01:05 AM Thread Starter
PSN Newb
 
Join Date: May 2019
Posts: 2
Terrible fuel mileage

Hey everyone! I'm sorta new to the diesel game so I'm here to ask advice from you experts!

I have a '03 F250 4 door short bed 4x4. Ive been getting awful fuel mileage lately and I'm unsure why. Heres a list of everything I've checked/replaced:

EBPS and tube - cleaned
Replaced all things brakes - nothing stuck
cold air intake - replaced filter
315/70/17 Cooper discover M/T @ 60 psi
4" exhaust from headers back
Fresh oil change with rotella T5
New glow plugs
Edge programmer on tow tune
Add a bottle of standyne to every tank

After checking the obvious, I'm still getting 9.4 MPG. No load, DD usually 10 - 15 miles per day and speeds averaging 30 MPH and I accelerate lightly. I understand that these trucks shine at 55 MPH but that's rare up here in Alaska. We just switched from winter blend to summer blend diesel up here but I didn't see a difference in performance or fuel efficiency.

Any suggestions?
XxNitewolfxX is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 05-19-2019, 11:06 AM
alleged moderator
 
tjctransport's Avatar
 
Join Date: Jul 2009
Location: in a loony bin in N.J.
Posts: 7,274
Re: Terrible fuel mileage

welcome to PSN.
you did not mention axle ratio, but even without that i can tell you the tire size is not good for mileage. also, the edge tuner is not helping either.
my untuned 02 with 265/75/16 tires gets 12-13 at 45 mph.

tom
owner of almost to many fords.



If you want the moral high ground, make sure you're not standing on a hill of horsecrap.
tjctransport is offline  
post #3 of 9 (permalink) Old 05-19-2019, 01:27 PM
PSN Veteran
 
s10mike's Avatar
 
Join Date: Jul 2013
Location: holland mi.
Posts: 890
Re: Terrible fuel mileage

I would check to make sure that none of your brakes are dragging. The calipers in these trucks suck. Also the slide pins freeze up and make the pads drag.
s10mike is offline  
 
post #4 of 9 (permalink) Old 05-19-2019, 04:37 PM
Project Shamu
 
Lt.Dan's Avatar
 
Join Date: Mar 2015
Location: Visalia, Ca
Posts: 1,846
Re: Terrible fuel mileage

Check for boost leaks.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1996 Cali F350 CCFB, 7.3 PSD, 2wd SAS, w/ 372,000 miles.
New Motor at 352,000, DieselSite Legendary Trans at 356,000 and many more


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1983 F150 SCSB Flareside, 302 w/ AOD Trans


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
2002 F450 SCFB, 7.3 PSD 2wd w/ 144,000 miles
SOLD
Lt.Dan is offline  
post #5 of 9 (permalink) Old 05-21-2019, 01:48 AM Thread Starter
PSN Newb
 
Join Date: May 2019
Posts: 2
Quote:
Originally Posted by tjctransport View Post
welcome to PSN.
you did not mention axle ratio, but even without that i can tell you the tire size is not good for mileage. also, the edge tuner is not helping either.
my untuned 02 with 265/75/16 tires gets 12-13 at 45 mph.
Yeah I'm unsure of the gearing. That's one thing I plan on looking into this summer. As for the tuner, I actually get worse mileage at stock.

Quote:
Originally Posted by s10mike View Post
I would check to make sure that none of your brakes are dragging. The calipers in these trucks suck. Also the slide pins freeze up and make the pads drag.
I just replaced the whole brake system about 2 months ago and checked last weekend, nothing sticking.

Quote:
Originally Posted by Lt.Dan View Post
Check for boost leaks.
I'll for sure do that. Is there any way I can do this or does it require a shop/special tool?
XxNitewolfxX is offline  
post #6 of 9 (permalink) Old 05-21-2019, 03:27 AM
Project Shamu
 
Lt.Dan's Avatar
 
Join Date: Mar 2015
Location: Visalia, Ca
Posts: 1,846
Re: Terrible fuel mileage

Google/Youtube "How to make a boost leak detector", several different ways to go about it, but pretty easy/straight forward.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1996 Cali F350 CCFB, 7.3 PSD, 2wd SAS, w/ 372,000 miles.
New Motor at 352,000, DieselSite Legendary Trans at 356,000 and many more


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1983 F150 SCSB Flareside, 302 w/ AOD Trans


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
2002 F450 SCFB, 7.3 PSD 2wd w/ 144,000 miles
SOLD
Lt.Dan is offline  
post #7 of 9 (permalink) Old 05-22-2019, 12:59 AM
PSN Veteran
 
s10mike's Avatar
 
Join Date: Jul 2013
Location: holland mi.
Posts: 890
Im 99.9% sure your gears are 3.73s. Boost leak is a good place to check, like mentioned
s10mike is offline  
post #8 of 9 (permalink) Old 05-22-2019, 01:04 AM
PSN Veteran
 
s10mike's Avatar
 
Join Date: Jul 2013
Location: holland mi.
Posts: 890
FWIW, i have basically the same truck, same tire size with a PHP Hydra tuner, Tony Wildman economy tune. Im getting a fuzz over 16mpg in town, fuzz over 20mpg highway. I never got much over 12mpg with ANY performance or towing tunes
s10mike is offline  
post #9 of 9 (permalink) Old 05-22-2019, 01:56 PM
dmd
Member
 
dmd's Avatar
 
Join Date: Apr 2009
Posts: 141
Re: Terrible fuel mileage

Is the thermostat stuck open and not letting the engine fully warm up? That will kill mileage when everything else
is fine.

'00 F350 Supercrewzer Lariet, PSD, Auto, 3.73, CC, 4x4, SWB, SRW, 160/30 w/Gearhead Tunes, 38r, S&B CAI, 4-inch turbo back exhaust, Adrenaline HPOP, BTS Trans, in-tank/pre-pump mod, heater/AC mod, Excursion sound panels, Harvest Gold and Black / Packages: Trailer Tow, Camper, Off-Road.
dmd is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the PowerStrokeNation : Ford Powerstroke Diesel Forum 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
Terrible fuel economy StrokeThese 1994-1997 Power Stroke Technical Info 4 04-19-2015 07:31 PM
6.0 terrible fuel economy - help - IIvonnyII 6.0L Power Stroke Technical Info 55 12-08-2012 08:23 AM
Terrible Gas mileage!! splatranger95 6.0L Power Stroke Technical Info 20 05-14-2012 04:56 PM
few mods and terrible fuel milage customsound 6.4L Power Stroke - Aftermarket & Performance 13 08-04-2011 02:00 PM
92 non turbo Terrible fuel Milage 97strokeonit 6.9 - 7.3L IDI Diesels 83-93 Model Years 3 02-13-2011 10:14 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