Lets start with:
- Do you have much experience tuning your truck (chip-wise)?
- Do you have the ability to burn your own chips?
- Do you have a wideband?
- Do you have Datamaster?
If you can't do your own chips and/or don't feel very comfortable with tuning your truck (intelligently), then I'd suggest looking up a local chip guru or contact one of us (Dig, Nolan, myself, etc....) to help you get a good solid chip. Tuning gas mileage (or any area of fuel) on these trucks can be difficult via long distance relationship, so I'd really emphasize that you seek a local who can get some seat time and really customize the chip to your truck.
However, if you answered yes to all of the above questions, then PM me and I'll help you out.
To answer your question, yes.....there are a number of things that can be done in the stock configuration to greatly improve gas mileage. From just cleaning up/customizing the fuel maps to implementing my EGR mod, you can easily see 40-50% gains in fuel economy with enough patience and knowledge.
HTHs
Hood