average GPM concerns

[g4sbrg]

OK so I took my first trip that was more than 40 miles down the road. My 2000 F150HD 5.4L gas and the drive train in the truck are rated for 8700 towing, my 5ver was at approx. 7600, I was hoping for 10 GPM but didn't come close, did reach almost 9 gpm in a family easy stretch between Texarkana and Dallas (60 to 65 MPH) most of the rest of the trip 8 gpm (a bit faster, windy, more uphill return) is this what I should expect ??? asked a guy at the dump station with a new tundra pulling a TT @7500 and he stated that didn't sound too bad to him. I am not using cruise or overdrive, pretty much made the whole 1000 mile trip running between 2700 to 3300 rpm Comments Please

[g4sbrg]

OK OK yall having fun with the typo!!!!! anyways it appears I have no major issues and have a few items that may help. SLOW DOWN, GO DOWN HILL. anyways that one comment put thing into idiot terms I understood HA. thanks guys, tune up. intake and exhaust may get a little but not much!!

Thanks

[cdlaine]

I'm in with a big block (8.1L 496) ... and 4.1 rear end.
I put a mid-ship replacement tank on to help with the
distance between refills. Out in the south west it is better
to start looking at the 1/2 tank left point.

Keep TV tuned, run both truck and rig as light as possible (re-visit
often), keep tires at proper inflation levels. Build a buffer in to
your gas budget for trips. I set cruise control at comfort RPM for
the Vortec/Allison combo. Work on smooth starts and stops (i.e.
plan ahead and stay involved). Keep an eye on the gauges. Learn
not to rush.

Know that many of us are in the same situation... I prefer sticking
to the flatlands unless I have a long enough time off to get to the
ocean.

Your MPG sounds good to me.

Charles

[agesilaus]

g4sbrg wrote:
is it more the weight or the exposure, I am pushing about 32 feet, some old literature on the truck stated not to exceed 60 feet above what the truck exposes, and do any drafting device show potential. V shape wedge on the top of the cab ??

From what I've seen most people don't think those wings and such do any good unless they are custom designed to fit the truck and trailer. Semi's use wings like which are custom fitted to the tracter and trailer that but the out of the box ones you buy aren't custom fitted. And even when they work they gpm improvement is small. Semi's drive hundreds of thousands miles per year and a small mileage improvement pays for itself. But you aren't pulling that fiver that far.

I'm a little surprised that you managed 9-10 gpm. You must of had a tail wind. 250/350 gassers are doing good to get that high a mileage pulling heavier 5vers.

[Jerallen]

03 Expy with 5.4 towing 30ft TT- I get the same mpg.

[Terryallan]

Yeah. you better stay home 10 GPM (Gallons Per Mile) sucks. You would have to fill up every 2 1/2 miles. :B

[4huskers]

I had an '03 F150 4X4 Supercrew and that's about what I got.

[Ductape]

You are fine. There are no magic bullets to increase mileage, but there is a steady trade in them because there are always a few believers.

[PUCampin]

If you are getting GPM (gallons per mile) you have a serious problem 🙂

Our Expedition with 5.4 gets 8.5-9MPG, sometimes slightly more. depending on hills, wind and speed. I have yet to break 10.:(

The frontal area and associated aerodynamic drag is the major contributing factor.

Power to overcome rolling resistance (this is where weight comes in) is a linear function of velocity. Going twice as fast creates twice as much rolling resistance.

Power to overcome aerodynamic drag increases as a CUBIC function of velocity. Going twice as fast takes 8 times as much power!

To feel this effect for yourself hold your hand palm out while going down the road at 25. Now accelerate to 50 and see how much more force there is against your hand. Now imagine that against the front of the trailer!

So even increasing speed a little, or getting a headwind, can make a measureable difference.

[Dakota98]

:B. Yep, that's about it.

I get 8mpg average trip. I only do 55 or 60 though at that.

One thing you can do to improve actual performance is install something like a K &N intake & most definitely a "Cat Back" exhaust, that really will make a difference in how the truck acts, at least it did for me. 98 Dakota 5.2L 🙂

[g4sbrg]

is it more the weight or the exposure, I am pushing about 32 feet, some old literature on the truck stated not to exceed 60 feet above what the truck exposes, and do any drafting device show potential. V shape wedge on the top of the cab ??

[Ridgerunner29]

I had that same truck until 2008. Pulling a 4500# camper I usually got 8.5 to 9.0 mpg. I would expect less pulling a 5th wheel with that truck.

[the_bear_II]

8-10 is about all anyone can expect with that combination of truck and trailer.

Here's how I have always looked at gas mileage.... The fun, family time and relaxation I get from being out in the RV especially when it's in some forest, near a lake or river far outweighs the cost of the fuel used.

I no longer worry about what mileage I get. I worry instead about the FPM I get (Fun Per Mile) Or (FPG= Fun Per Gallon).

By the way on level road or gentle rolling hills I use the cruise control and overdrive. It's one less thing to worry about.

[downtheroad]

Sadly, that's what you are going to get hauling a 4 ton sail.