Since being on this Forum I've been feeling fortunate that my 04 4x4 lifted (6")Crew running on 35" Toyo AT gets overall better MPG than most others on this Forum. During a two week summer road trip last year that covered almost 5000 miles we averaged 19.5 MPG. This was a slow sight-seeing trip with the cruise on most of the time, running 50-62 MPH, some less 45-50 MPH.
May 6 of this year I had JBA headers installed on my 5.4L, and to complement that I installed Flex-a-Lite e-fans and ASP underdrive pulleys over the Easter weekend. This past week was my official MPG test in 2006 with cruise on 53-62 MPH. Conditions were good and winds mild. When the low fuel light went on on my first tankful, my trip odometer displayed 592 miles or 947 KM. My fuel fill-up to full used 28.2 gallons or 107L....that relates to an honest 21 MPG.... not all my driving includes such tests...I do hammer it at times...but fuel cost are teaching the right foot some new habits.

My mods:
Pro-Comp 6" lift w/add a leaf
Toyo 35" 13" 18" AT on 6089 Pro Comp 18' x 9" (50 lbs air front/back)
(these tires and rims weigh in at 105 lbs, stock is 85 lbs...the 20 lbs weight penalty is not all that bad compared to other tire combos).
True Flow Intake
Flowmaster 40 SS muffler swap
Superchips 1714 91 octane
JBA Headers
ASP u/d Pulleys
Flex a Lite e-fans #270
Synthetic in engine and power steering
ARE cover

Norm

 

Wow, that is very good. That has a lot to do with the 53-62 mph too. If you took that same test at cruise @ 75 I bet it would be in the 18 range.

 

Your mileage is very good. I get about 16 mpg at about 70-75.

 

I wish I was getting that... my problem in florida is either stop and go traffic or 80 mph highway driving which is huge diffrence over going 50 on cruise control.... i get around 15 mpg on 33's

 

That's pretty impressive, much better than I get.

 

Wow thats real good! I have a question, Is the Flex-a-lite a kit made for our tucks?

 

Those pullies drop your highway mileage about 1-2mpg, and city +1-1.5mpg. Those are rough numbers but pretty close. I sold my pullies as I had hardly a gain in 0-60 performance (it would need a tune to shift earlier for better times). It's basically regearing the truck at the crank, and if you're shifting at 5400rpms your powerband is at its max earlier and you need to shift a bit sooner. My own observation. Before my 37's I was getting 22mpg or so, and hit 23 at times and the same speeds you're speaking of. I was running premium octane everytime. With the pullies I had more low end, less top end. I was able to chirp the stock 32's at times.

 

This weekend I got a chance to see how much running at 60 mph vs 70mph changed the fuel mileage in my 04. I had the IMPG and AMPG displayed on my Edge. At 60 mph IMPG was bouncing between 19-22 mpg and at 70 IMPG was 13-16. I knew that there was going to be a differance, but I never thought that it would be as big as it was.

 

I drove to our place in Grand Bend last week, the US side is mosty freeway (70) and once crossing into Canada it was 50-60mph straight county backroads. I did the speed limit the whole way (that was tough) and I averaged around 19 mpg and that is with a k&B drop-in and exhaust. I always thought Candian speed limit were really slow, but they do wonders for Mpg.

 

I'm jealous.....hopefully mine will get better with age (only 2800 miles so far). I am avg 13.2 mpg. About a 50-50 split between highway (80-85) and city (45-55). 06, F-150 Screw, 4x4, 3.73, 20" Factory, No other mods yet. My wifes 03' expy gets 16.3 (not 4x4 and she has a lighter foot)

 

At the end of the month I plan on puttin steeda underdrive pullies and set of efans. Along with a edge most likely. Unfortunately I have a 4.6 do you all think I would see a big difference running level 3 with 93 octane?

Also has anyone heard of a new programmer coming out by sct?