Fuel Mileage 6.4 or 6.7

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I have been out of the Ford diesel world for a while so I have no clue about this answer.

Between the 6.4 and 6.7 with "fuel mileage mods" in mind, which one would get the better fuel mileage living in front of a 5,000lb loaded trailer with a good ton in the bed at all times?

Please forgive me if I asked this in the wrong section or missed a thread comparing the two all ready.

Thank's
 
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My current work truck is a 2014 F350 4x4 CC long bed. Being that the truck is a State vehicle it has to stay %100 stock! The truck is loaded down with a good 2,500lbs and it gets about 14mpg and less just going by the computer. I love the power of the 6.7 it will jump right up to 70mph in a heart beat! The only problem I have with the truck is maintenance keeps telling us not to let the truck idle over 20-30min. Problem with that is we have battery chargers and strobes we have to have on while we are out working. No problems as of yet but this truck did get all LED strobes.

Edit: One thing I don't like about the new state truck is it's all ready sagging in the rear. Thats with maybe 3,000 miles on the truck since Feb of this year

This truck I'm asking about will be my own business truck, so it can get any fuel mileage modifications it needs. Does anyone have any fuel mileage numbers they could share with me?
 
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Forrest Nearing said:
Your maint division should install high idle setups. This will help keep things clean during idling
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LOL I was just happy to have the stripes on straight and a cruise control! I wasn't about to complain! It is much better than the ole 200,000 mile 5.4, 2wd, 2008, been on fire twice, wore out truck we had! It carried the same loads and did good for what little balls it had but it wasn't safe! I got stuck in that truck all most everyday during the winter!
 
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Reading other threads I see where y'all talk about 6.7 engine differences between commercial trucks and regular pick-ups. I noticed on Fords website that the commercial 6.7 trucks where only 300ish HP and 600ftlbs compared to the 400 & 800 numbers. I tried asking my local dealership and none of the salesmen even knew Ford rated them different.

The new truck will be a XL model and I'm debated on getting a F450 or F550
 
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The 14' 450 I drive is a XL model. 300hp rating. It will do whatever is asked of it power wise even towing around 26k gross.

Heavy dude though 18,500ish with a 32' gooseneck empty.

Averages 10.5mpg.
 
I would skip the 6.7 then...

get the 6.4, do MILD mileage mods, and you'll be good to go... a 5.7 chassis cab truck UNLESS it's a 450 lariat/kr/platinum will have the anemic turbo and you'll likely destroy it with mods. so plan a turbo swap

I think dollar for dollar, you'd be ahead with the 6.4 based on what you've said
 
estrada5.9 said:
The 14' 450 I drive is a XL model. 300hp rating. It will do whatever is asked of it power wise even towing around 26k gross.

Heavy dude though 18,500ish with a 32' gooseneck empty.

Averages 10.5mpg.
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Back in the 7.3-6.0 days it was explained to me International branded versions will see a life of WOT everyday pulling loads. Where the passenger car versions will rarely see WOT and almost never come close to the max load rating. Passenger version numbers are just for bragging sake.

I was wondering about the talk of different turbos between the engines instead of just programing. Is there any other differences?
 
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It's a "normal" turbo. Has fomoco iirc on the compressor cover.

I'm always pulling something and in a hurry so mileage reflects that.

I like it a lot (never thought I'd say that about a ford) other than the outdated interior and vinyl seats.
 
It's a "normal" turbo. Has fomoco iirc on the compressor cover.

I'm always pulling something and in a hurry so mileage reflects that.

I like it a lot (never thought I'd say that about a ford) other than the outdated interior and vinyl seats.
 
estrada5.9 said:
I

I like it a lot (never thought I'd say that about a ford) other than the outdated interior and vinyl seats.
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I love the 2014 XL seats, they seem to have better lumber support and deeper cushion on the seat bottoms. But my 08 had the old school bench seat.
 
I sweat a lot that's why I don't like them need to get a breathable seat cover for them.

They are very comfortable don't get me wrong ha.
 
estrada5.9 said:
I sweat a lot that's why I don't like them need to get a breathable seat cover for them.

They are very comfortable don't get me wrong ha.
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Yeah, I'm trying to keep the truck interior clean at least for a year! I keep a small brush in the doors and sweep the floors and seats out everyday. Then once a week use simple green on the grab bars and arm rest.
 
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