Higher speed mpg? - PowerStrokeNation : Ford Powerstroke Diesel Forum
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old 03-03-2013, 04:51 PM Thread Starter
PSN Newb
Join Date: Apr 2010
Posts: 15
Higher speed mpg?

I drive my Excursion around 700 miles every other weekend for visitation. I usually drive 65-70 round trip on US-58 to I-85 from Va Beach to Raleigh and back twice in a weekend and mpg is 18, maybe 18.5. I top off at the BP in hilltop and go. I went I-64 to Richmond and I-85 to Raleigh on the way back this trip and drove 80-90 most of the way with the flow of traffic. I got 19.7 hand calculated this trip. I made no changes and I am running the canned tow tune on the SCT. Is that normal? I don't usually go that fast, so I was wondering. My average for 14k miles of mixed city and highway is 17.4.

I am glad I didnt take the Liberty CRD. I just put a GDE tune that got my mpg up to 22-23 average thinking to get rid of the Excursion seeing as it's more than I need for me and my 5 yr old. But there is no way I'd have been willing to go that fast in the jeep, and it would have killed the MPG anyway. The excursion is a road trip machine and seems to handle well and have plenty of power, the jeep is dying off at 70. It'll go faster, but has to build up to it.

I am wondering if maybe a Looney tune would help the Excursion or if I should be glad of what I am getting considering I keep seeing folks complain of 12-14.
buddy357 is offline  
Sponsored Links
post #2 of 4 (permalink) Old 03-11-2013, 01:26 AM
PSN Local
scagle1's Avatar
Join Date: Feb 2011
Location: Lago Vista , TX
Posts: 156
Re: Higher speed mpg?

My theory is you reach a point where no more fuel fits thru the line at a single moment and the truck still has speed left so you start gaining MPG when you surpass that point. Completely ridiculous I'm sure.
Maybe you had the wind at your back , temps outside were optimal , you got some fuel with a bit more than the 15ppm sulphur....
On a side note on a 2001 Freightliner classic with 500 Detroit and a 13 speed , i normally averaged 5.7-5.9 mpg. I came across I-40 in Arizona and New Mexico late one night in excess of 90mph most of the time and came in right at 7 mpg , best the truck ever did on fuel.

03 7.3 with the new nose 8" and 37's 124k original and adding slowly

Sold - 00 X, 01 350, 02 350
scagle1 is offline  
post #3 of 4 (permalink) Old 04-08-2013, 06:36 PM
PSN Local
Join Date: Dec 2011
Posts: 60
Re: Higher speed mpg?

I've found that every setup has a sweet spot. It depends on your engine powerband, gearing, wheels, aerodynamics, whatever. But when you find your sweet spot, you drive that speed. My old setup was a 7.3 w/ 6 spd. It loved 75, I could beat 20mpg all the way across Ohio. The new Excursion is a 4x4 auto with 4.30's and 10" wide tires - and it likes 62 .

E99 F350 CCLB 7.3l auto
T-case with a shifter!
Bone frakking stock
copracr is offline  
post #4 of 4 (permalink) Old 07-02-2013, 05:11 PM
MPG Moderator
Dave Whitmer's Avatar
Join Date: Jul 2007
Posts: 1,076
Re: Higher speed mpg?

Your Interstate run gets you better MPG because it involves no stop-and-go.

Stop-and-go driving involves repeatedly accelerating up to speed and that requires additional energy to accomplish. Steady speed Interstate driving - even at a higher road speed - does not impose the acceleration penalty.

2000 F-350 SC 4x2 6 speed
3.08 gears Gear Vendor Overdrive
Slammed 4"
Rugged Air Dam
315,000 miles
Dave Whitmer is offline  

Quick Reply

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


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

Email Address:


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

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