The first part of your question is easy... Don't use gas!

The next is harder to guess, but I'd bet you've got a winter blend of fuel. Lighter oil, more additive, and less energy per gallon of fuel.

I wouldn't even put it past some companies to "stretch" a gallon of fuel with cheaper components so as to increase profits. Notice, I'm not accusing anyone of anything. It's just that most of us have suffered through this sort of thing and there's usually a good reason.

If your filters are clean and she's not bellowing clouds of smoke, and if your performance hasn't fallen off, then I'd probably blame fuel. I might still check lift pressure and double check turbo and intercooler fittings.

In the end, though, it's likely to be a combination of heavier winter air, lower tire pressure due to colder temps, and less calories per gallon of fuel. (Much like adding alcohol to a gasser... Cleaner burn, but reduced economy because of less energy per unit of measure.)

One more thought... Make sure you don't have a brake dragging or other mechanical problems that would put constant load on your truck.

 

You beat me to it, I was going to post the same thing....

My mileage changes all the time, seems to change with each fill up from different places, I tend to go to the same place now and it has stayed close to the same, went down a little with winter coming....

Change your fuel filter and then check it again after while, if it's dirty change it again...that may help...

 

When was the last time you ran some Rotella DFA or FSPS Fuel Additive? Might want to try running some a see if it helps.

 

ok...I have no idea what you mean by that additive....what is it? Where would I get it? Where would I add it? SEEEEE!!!! I'm too much of a girl to drive this truck!!

 

Peach what part of Atlanta? I am in Winston just west of Douglasville.


Sam