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Horrible fuel mileage

5K views 9 replies 5 participants last post by  Powerjoke11 
#1 ·
Hello everyone. I just recently bought me a used powerstoke, my first at that. I bought a 2015 ford-350 4x4 dually. Truck had 285's on it. It was stock until last weekend, before tuner I was getting bad mpg's. I recently bought a ez lynk tuner with GDP tunes. I baby the truck and it still gets bad mileage like 11-12 max. Love the power and truck but my dodge gets over 15 with 35's. Any secrets or custom tuning company working on mileage that y'all know of? Thanks!
 
#4 ·
Is this city or highway...what speeds you running...etc....

Milage is a hard number to determine, but I can see 14.5-15.5 with a mild dpf-on tune and 35's and a level when i run 70 mph on the freeway consistently....but im not a dually and I got one step lower gears than you - 3.55. Anything over 65-70 mph kills milage immensely also.

the numbers sound about right for city driving, driving with a light load in tow, or driving 80+ mph, a dually to boot. Prolly has the 3.73 rear end in it and that ain't helping

1500-1700 rpm is the sweet spot cruising for milage, while keeping boost down to 4-5 psi.
 
#5 ·
What gearing do you have in the rear? I have 4.30, I do not expect to get much more than the 12.5 mpg I currently get (no matter if I am in town, towing, highway, etc...). I am still running stock, but will be buying a DPF-on tune here in the near future.

Cale
 
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#10 ·
It could be the tuning causing the truck to regen all the time. I had canned sct tunes before i was deleted and saw 16-18 mpg with 3.55 and 33's.
 
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