02 Dmax MPG ??

[KrazyNate]

I noticed a couple sticky threads about MPG on the different engines.. Im not sure what series engine my 02 has... LB7??

Anyway, sorry to start a new thread, but.... I have not seen better than 14 MPG since I bought it back in Oct.. GM warranty bought eight injectors for me the week after purchase because my first tank of fuel was about 9 MPG :eek

It is a crew cab, which I suppose is a little bit heavier than the standard and E cab models, but why do I get such terrible mileage??? Everyone I talk to says 18-20 MPG all the time..

Are they feedin me pig stuffing or what??? Just curious, as Im starting to lean towards a Cummins..

Save me before I turn to the Dark Side..... hahaha

Thanks

[Mark Rinker]

That sounds low, but depends alot on the following factors, in order of importance:

1) Driver habits - average speeds, 'jackrabbit' starts, heavy braking, etc;
2) Free breathing - clean air filter, unobstructed exhaust;
3) Engine efficiency - complete and efficient fuel burn via good injectors, turbo functioning properly, engine operating at 180-190 degrees F;
4) Rolling resistance - properly inflated tires, brakes adjusted properly, use of sythetic lubricants in differentials and transfer case

We average 13-14 towing a 30' trailer with average 6K loads with our 2002. Empty I have seen 18-19.

Q1) Do you see black smoke from your exhaust at any time? If so, when?
Q2) When did you last change your air filter?
Q3) Is the power and accleration of your truck good? How much diesel rattle? What is your average cruise water temp?

[KrazyNate]

Thanks for the input...

I havent noticed any black smoke.. But then again, I dont follow myself...

Air filter, is about 10k old which seems old to me, but my indicator is showing a clean air filter.. Should I change it anyway??

No rattle and the power feels good.. For being bone stock anyway.. My operating temp is good, usually around 200 F... However, Im not always at operating temp as my commute is only about 6 miles.. So I do understand the low economy.. BUT... When Ive gone on long, highway trips, I still only got 14-15 MPG.. Towing a our trailer, about 7k loaded, I get less than 10 MPG...

Would a fuel filter cause low MPG??

As far as driving habits go, I do have a heavy foot a lot of the time.. However, I have experimented quite a bit to try and remedy my low economy without much, if any success.. I very seldom speed...

Exhaust is stock.. No mods, no kits.. Intake as well.. No chips or programmers..

Tires are brand new, recent alignment and good pressure.. I run about 45 psi...

Thanks again for your input Mark

[Mark Rinker]

I'd say you are due for an air filter and fuel filter if over 10K each. A blocked air filter will kill mileage. A blocked fuel filter will kill fuel injectors.

I'd say your low mileage is the result of a heavy foot and short commute. It should bounce back on long trips.

Change your filters and run a good fuel treatment, would be this Dr's prescription.

[beeler]

I agree with Mark. Your commute and loaded milage don't sound out of line. The highway part should be better. I have an 02 CC ong box. Running empty on the highway I get 16.5 to 19. Depends on wind, terrain, and the position of my right foot. Twenty plus is very possible if I drive like I'm following "older" folks to church.

[KrazyNate]

Thanks for the input guys... Ill try those options and check back...