Horrible Mileage...What is the prob??

Powerjoke07

Powerjoke07

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Joined
Sep 17, 2009
Messages
9
I have an 07 6.0L and get 10mpg or lower. I got a little better mileage, but not a whole lot, when I got it. I have a SCT by Innovative and I run it on the Agg Street tune that came with it. I dont know what the problem is and I drive over 100miles a day so it needs to be fixed. Ive even started to drive slower but it doesnt seem to help. Thanks for the info
 
Boost pressure? EGT temp? Low power or towing? Any codes? Excessive smoke?

I have 3.73 gears, 2wd, 4 to 6 psi, 550 to 650 degrees. Hand calculated 17 to 19 mpg hwy depending on wind 16 to 18 mpg city. Same tune from Innovative with mods below.
 
I have a '06 F350 CC 4x4 6spd 6.0l that i get 16mpg out of consistantly, have seen 21 mpg goin to California.. Have seen as little as 8mpg a few times when i had Engine issues
 
Tire size & psi? Are you reporting highway mileage or city? There are soo many things that factor in to mpg. Things like the fuel consistency & quality, additives, asphalt or sectional concrete roads.

You might also want to check to make sure you'r front hubs are free and aren't locked if you have 4wd.

Also are you using the lie-o-meter or hand calculated?
 
My boost 7-10 at highway speeds. Power is normal. Egts are 600-700. Power is not a problem. Everything runs fine, or seems to, its just that it gets horrible milage. My tires are 265s with the rated psi. I only get 300 to 350 miles on the highway with a 30 gallon tank.
 
Are your brakes dragging? When was the last time you changed oil, airfilter, etc? Also in the winter, you will usually see winter blend fuels which will cause a drop too. I get 14.5-16.5 and thats with 190's and my bad driving habits. If its an 07 its probably under warranty, take it to the dealer and tell them they need to fix it.
 
I thought my truck got bad mileage but its not as bad as yours. I do mostly 70% country roads 30-50mph with stops every now and then, and some highway usually 75-80mph. I get 14.5mpg with the xtreme race file and only about 13mpg with the stock tuning on 35x13 tires with a small lift.

Gotta be something wrong with your truck to get that bad of mileage, cruising numbers seem to be normal EGT and boost wise.
 
I typically get 300-350 miles out of my tank... Your truck looks like a shortbed as well. I don't see how you could be stuffing in 30 gallons on a fillup, my fillups are typically 25-26 gallons.
You may not be getting as bad a mileage as you might think.

By the way....... Not a big fan of the username. (opening post)
 
If you do the harpoon mod on the tank you can get 30 in there no problem. I have been doing it for 5 years, plus you don't have to worry about it foaming up time and time again, and squeezing every drop in there. when it kicks off, its full.


here is a link to it.

http://65.121.190.196/diesel/intank/
 
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