I asked this at the other DMAX forum and want to see what the consensus here was and since this site has been around longer and most of the people here are over there as well I thought I would post this any way.
I have only had my truck for a week and I already need to fuel up. The wife says " You already need gas and it hasn't even been a week"? I told here it was over 400 miles on the trip counter. I probably could get 450 or a little more out of this tank if I took it down to the end but I'm not willing to chance running it out of fuel. I figured out today after filling up, that I have around a 30 gallon tank. I was almost on E and took 28 gallons before I couldn't squeeze anymore in. I am using Stanadyne performance and just changed the oil with Rotella T 15W-40 and put on a new spin on tranny filter on Friday and was also thinking about putting on a new fuel filter soon and I also put in a new tough guard air filter last week. The motor only has 34,900? or so.

My question; Is this normal mpg for this low miles because it is still going through break in or is this what I can expect from now on:confused:

What can I do to improve the mileage besides buying a programmer? I will buy one eventually but I have to waite til I can afford one later this summer or fall. I have 245/75/R16's on right now and in the fall I will put on my 265/75/R16 Toyo open country tires that are siped for the majority of the year. I have purchased a PPE boost increase valve and a BD power LH exhaust manifold which I am waiting to arrive in the mail so I can install them.

Any suggestions on what I can do to get better MPGs' without sheling out a lot of money? What about using better fluids like synthetic in the engine, trans and diffs (Which I will when I can afford it) Anything else like mods I can do myself like the Kennedy airbox or something else? :help:

Thanks Brad

You are saying 14 mpg? It should get better than that. Maybe get a reflash at the dealer? Hopefully someone eslse will chime here with some better suggestions. My dually is getting around 17 mph. BTW you have a 34 gallon tank if ya got the long box.

For the fuel up here right now, that's about right. Until it gets switched back over, we are getting about 15mpg. Wait until it warms up.

yup..winter blend really hurts the mpg...wait till summer blend comes out and you should see 3-4 mpg better..

Change out the wife to a more understanding one...J/K

I see a difference in milage if I keep the rpm's at or below 2000, see if that may help also.

I am running an average of 450 miles per tank which usaully comes out to be in the 17-20 mpg rang witht he TC and trailer more like 15-17.

I feel blessed with mine, I keep mine at 2000 rpm or 65 mph and I average about 24 mpg.

I'm running about 14-17 with the Predator on 65hp. I see a lot of people getting better, but I don't keep it under 2000 RPM's. I'd get run off the road here in Southern California.


Andy

I'm somewhere between 15 - 17 Mpg. I do a mix of highway / city driving and drive like a normal person.

If this is your first diesel, there is a slightly different way to drive it. When I first got mine, I could not get any better than 12mpgs. Now, I try to drive the speed limit (or at least not too far over), do not necessarily need to be the first one off the line and try to keep the rpm around 2k and my last tank averaged 18.7mpgs. Yes, our new blend of fuel has helped, but it has been more my right foot than anything wlse with no other changes. This is with a 6" lift, 35's, and a big ass front bumper.

I feel blessed with mine, I keep mine at 2000 rpm or 65 mph and I average about 24 mpg.

2000rpm's and you are only running 65? I'm am at 1650-1700 when I am going 65. I guess with stock tires you might be close to 2000, but when I had stock tires 70mph = 2000rpms. No complaints if you are getting 24mpg's and your odometer is correct.

Bring on the Summer Blend..... With the way prices are climing just in time for the summer.?...... I just might go Buy a Horse.
No place to build a birds nest in his airbox....:mad: :mad:

I run at 65 (between 1800 to 1900 rpm's with stock 245s) and am getting right at 20 running around and 22 - 23 on the freeway empty. I'm running my edge on lvl 3/5.

Steven

Thanks for the input so far.

You have an LB7, could it be injector issues??
Do you know if they have ever been checked, or changed?

I was down around there (15mpg) solo until I recently had the injectors changed. Now I'm averaging 11-12mpg pulling my fiver. I haven't had a chance to measure it solo. Are you awhere if the injectors have been changed in your truck recently?

Brad

I have a 2004 LB7 and I found the best MPG is by maintaining around 1800-1900rpm which is around 60-62mph. 2000 rpm is 66mph and slightly worse mpg.

Bigger tires will mean you are actually going faster than what your speedo says and I do have LT 265/75/R16 and found overall my mpg dropped a little..hard to tell because I took off the 245's real soon after I got the truck but I would say it was around 1mpg drop worst case.

My truck always got good mpg..since brand new...I never saw any change with break in say at 10k or 20k miles. I did notice slightly better throttle response after about 20k miles.

Also my truck stock is low on power...not sure if it has changed since I have not checked it...but I believe it dynoed around 229 rear hp versus 240 rear hp when only had around 15k miles on it. It could have been the injectors since getting new ones at 55k miles the truck runs better.

MPG has stayed about the same if not a little better since new injectors..but since ULSD I would say I down a bit from my best MPG readings. Current mileage is 103k.

I get about 13.5 pulling a loaded 32' equipment trailer at 60-65. I get 17 or so otherwise, and used to see 19-20mpg out of a tank pretty often. I drive with a soft touch on the throttle pedal too. The cruise control will kill your mileage because it is really agressive in maintaining speed.

Best for a full tan = 22MPG
Worst for a full tank = 16MPG
Average Winter = 17MPG
Average Summer = 19MPG