What can I do for better mileage don't care about more power right now. 03 dodge cummins:

 

smarty intake, exhuast!

 

What he said

 

what they said haha

 

have all those now what? i'm plannin on puttin the free spin kit on the frontend and possibly a boost cooler.

 

It really depends on how many miles you intend to keep your truck...$$$ in mods that provide minimal increases will pay for a lot of fuel, and you may never see the return on your investment.

Although most of you will balk, drive slower. 55 to 60mph will yield my best mileages, and depending on the terrain I have hand calculated 25mpg (back to back tanks, 21mpg overall trip) through North Dakota (almost flat, good tail wind). Driver input has probably the biggest impact on mileage numbers.

 

Free spin kit did not do anything for me. My best mileage increases came from inflating my tires to 80 PSI and keeping my RPM at 1800 or below.

 

What they said^^.
If you plan on keeping the truck for a long time, put the $$$ into it.
Paying at the pump, or paying in one lump sum for a mod, both hurt. We usually feel better about the latter because we only feel the "sting" once, versus every time we fill up.

In larger vehicles like these slower is definitely the key.
In my DD Scion, the "sweet spot" is about 75mph on the interstate. That nets me about 35mpg on average (which is why I bought the ugly little in the 1st place ).

My Landcruiser's sweet spot under the same conditions, is around 55-60 as stated. 6000# plus, lifted on 33's, brush bar and pushing the aero-dynamics of a brick.

You could "de-mod" the truck.
Lower it if it's raised, use smaller tires for less resistance, remove any brush guards, etc., to lighten the truck, things like this.
But again, you're talking about a lot of $$ that could just as easily buy fuel.

The best advise again IMO, is seen above.

Slow down, inflate the tires for the road, and if you want to install something, spend a few cheap $$$$ and buy a vacuum gage, aka: fuel mileage indicator.

You can J.C. Whitney them for cheap, or just pick one up at NAPA, PeP-Boys, or freaking Wally Mart.
Doesn't have to cost over about $20.00. They all do the same thing.

Figure out where the "sweet spot" is for your type of driving. Where do you do most of your driiving and how (towing, hauling, empty cruisung?).

If it's really mixed driving, put a small red dot on the face for say interstate, a small white dot for in town, and a lime green one for loaded (heavy not drunk).

A quick glance will tell you if you're "there" for the driving you're doing at the time.
It becomes a bit of a game after while and challenges your to operate more fuel efficiently.

Just a few tricks I've picked up along the way.

 

thanks for those tips. i backed it down from 75 to between 65-70 and i can tell a difference in the mieage. can i get a little more info about the vacuum guage.

 

Sorry, being from the "gasser" world, that was my first response.
I'm not sure that a vacuum guage will work the same on a diesel.
Maybe someone more familiar with the diesel's function can help?

Here's a quick youtube on the vacuum guage and it's function. Essentially, you want to keept the #'s high to keep your fuel usage low in a gasser.


Here are some other ideas and a couple of websites you can check out for more information on diesel specific applications for fuel monitoring.

Floscan Instrument Co. Inc.

Cheap Multi-Gauge / Fuel Economy / Code reader - Diesel Place : Chevrolet and GMC Diesel Truck Forums

Best Gauge/Monitoring Device? - Diesel Place : Chevrolet and GMC Diesel Truck Forums

Aftermarket MPG gauge or display? - Diesel Forum - TheDieselStop.com

Looks like a scanguage seems to be the guage du jour of the diesel crowd for fuel economy monitoring.