dont get a Powerstroke if you want great mpgs, 17mpg at 80-85mph

From what I'm reading, no stock diesel will get good MPG at 80-85. I'm seeing that keeping your speed to 75 or less is the best way to good mpg.

mine aint stock, but 2000 rpms or lower get you the best mpg's

That's what i'm seeing. There's also the factor of wind resistance that grows steadily over 70mph. 80-85 shouldn't be 2000rpm or lower unless you've got different gears... no?

no, im at 2150-2400rpms

ok, i misunderstood what you were going to use it for, missed the hauling part.

my truck is bone stock other than the programmer, at 70mph i'm turning 1800rpm with the 6spd. gearing is 3.73 i believe and mileage is hand calc. i have noticed whether i cruise at 45 or 65 it does about the same mileage wise. over 70-75 and it starts getting worse.

mine is extended cab short bed. plenty of room for me, the girl a 11yr old kid and baby in carseat and all out stuff lol.

i love the truck so far, but it could do a lot better with a proper efi live tune. and so far my favorite to sit in for a long ride without getting fatigued.

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as for the 6.5.. not sure on the mileage but there are almost no mods for those it is what it is for the most part. power isn't bad, my buddy towed my old gmc1500 on 42" tires etc on a 24' gooseneck and it moved it along just fine.

I'm seeing some mod's for the 6.5, the one i'm looking at is a 2000 with a no start condition for $1k. I'm seeing a common PMD failure for these and was thinking this might allow me to get into a diesel to "try it out" without going out and dropping 15-20k on a decent used truck. I know a 6.5 is hardly the same is a 7.3 powerstroke, a cummins or duramax, but at that cheap, what do I have to lose?

Available 6.5 mods through this company: SSDiesel Supply :: GM 6.5 TD Specialists, PMD failure, FSD heat sync kit.

Seems to know his stuff around these motors.

At any rate, the guy just emailed me back to say that truck was gone already (listed it yesterday), lol.

I wouldn't be destroyed if I got a diesel and it got 17-18mpg, that would be passable. I had a tahoe I sold because it got 12mpg, that was too low, and didn't have a bed. I'd obviously like to get 20+ though. lol.

cheapest to tune to 20+ i think would be a mechanical cummins truck.

my duramax gets around 17.5 consistently, until i drop a grand on EFI live and really do some tuning :tu:

I was under the impression there wasn't a lot you could do to tune a mechanical cummins...

I got 24 MPG in my 98.5 Cummins its 4x4 and has M/S tires on it and they are fairly aggresive. All ive done is straight pipe the exhaust.... Also has a new Exhaust manifold, the stock one had it last day...