engineermike

Dawg, you and I were thinking nearly the same things, 'cept I went about it a little different. I went on a 255 mile trip and decided to try and get a fuel economy curve for the truck. The goal was to go 5 miles with no cars within reasonable distances in front or behind me. EB SuperCrew with 3.15 gears, 4 passengers, bed full of stuff, bed cover, and 93 octane Exxon gas with horsepiss (Ethanol), ~2000 miles on the odo.

mph mpg
55 30.1
65 26.8
70 24.5
75 20.9
80 19.5

I'll probably make another thread for this so it doesn't get lost.

DieselDawg

Those are actually interesting numbers...the big drop off of mpg at speeds over 70. Those 3.15 gears seem to work for ya'

ilmo

Dawg,
Not exactly what your test were, but this is what I got on a short interstate trip. My overall average for the 7000 miles combined driving is 18.0.


Here is my latest checks with just under 7000 miles:


After filling up and getting on the highway I got this on a 61 mile trip.
Interstate @ 67 MPH average and got 21.1 MPG. I was driving south with ENE wind at 5 to 10MPH and light to moderate traffic.

Dtm030

I have a couple of youtube videos of mine the other day if anyone is interested.


3.73 gears. 87 octane.

Spec3

From my trip yesterday...Richmond, Va to Bowie, MD...some stop and go traffic on I-95 in Fredericksburg, VA....

3.73 rear and 87 octane...A/C on full blast and 97 degrees out.

ilmo

Here is what I am getting after driving one hour as close to 70MPH as I could get. This was right after I had filled up at a Shell and 87 octane. Hand calculating those numbers, the average is 20.57 MPG.

I was driving east for half of the trip and was getting 20.8 MPG, then turned south with a head wind and it dropped to 20.4 MPG. Temperature of 91*F.

The truck does seem to be doing fine, although it does have a very slight shudder in 1st gear @ 3-7 MPH.

truckerdude

wasn't much of a headwind if it dropped only that little bit. around here the winds are 15-20 with gusts to 25/30 and you can 1-2 mpg.

ilmo

Here is another one.
This one was as close to 65MPH as possible:

c.kenney1989

My road test exceeds your expectations by a 'little' bit, but i took my 2011 f150 lariat 3.5L on a road trip from north dakota to florida, up to toronto, canada. all the way back to north dakota. Trip A totaled over 6000 miles, well over 200 gallons of gas used, and the entire trip averaged over 20mpg with over 1000 miles driven within city limits. Must say im pretty satisfied!

ilmo

Yep, sounds like you got a good one. What was your top MPG and at what speed?
Looks like mine is going to be about 20.4 @ 70, 22.5 @ 65. I have gotten this on several occasions. Haven't tried it at 60 or 75, yet.
My truck now has 8400 miles on it and it is averaging 18.2 MPG combined. Trip B has never been reset since new.