I am new to the forum and to diesels as well. I have read near all the posts here and I have to say you have taught me alot.http://www.dieselplace.com/forum/smileys/Clap.gif


I have a 2004 GMC extcab duramax lb7/allison 4x4 with 315s. I use this truck to drive to work and to pull a light ski boat every once in a while. I didn't need the advantages of a diesel but I just had to have one!


I am looking to increase my fuel mileage. I know by doing this I will probably gain some hp. mileage and running gear safety is #1, hp is #2. Any help is greatly appreciated!Edited by: bub_breeding

First of all WELCOME.. You need to post a pic of your truck for all to see. I think you will find all the answers to all of your questions on here somewhere. If you can not find them then ask. We are always here to help. Once again congrats and welcome.

LB7 or LLY?

I have a 2004 GMC extcab duramax LB7/allison 4x4 with 315s.


I know that my mileage calculations went down to be 15 and some change because of the 315s. I write computer software for a living so I made a little program that you can enter you tire size and it will recalculate you mileage based on a ratio found from "X" tire size to stock 245s. With the new calculation I am around 17.

Well you can run a programmer (many to choose from), Edge, Banks and a few others you may want to do some research on and decide what you like the best. You will find opinions from everyone here and it will be up to you to figure it all out.. Good luck..

I have done alot of research on the different "chips". There are some great discussions here for Banks vs. Edge, but it seems the debate was more for hp and other pros and cons. I did not see much information on fuel consumption.


Are all the programmers / chips going to benefit mpg about the same (1-3 mpg more)?


What about... exhaust or afe intake?

Exhaust and intake will make your truck run better. With a programmer you will see some increase in fuel consumption. Could not tell you exactly how much as power is addictive and once you have it you will never keep your foot out of it. I know that in the beginning I saw about a 1.5-2 mpg increase in highway driving. I was happy...

Can you post or email me this program you speak of?

Exhaust and intake will make your truck run better. With a programmer you will see some increase in fuel consumption. Could not tell you exactly how much as power is addictive and once you have it you will never keep your foot out of it. I know that in the beginning I saw about a 1.5-2 mpg increase in highway driving. I was happy...


If you keep your foot out of it you should actually see an increase in fuel mileage. Not a decrease.

I have had good luck with my quadzilla box bub,catch me up in the hill's one weekend and we can put the tune in your truck and see how you like it.

I have the Attitude and Predator and with either of these I have not seen an Increase in mileage. So do not expect to see a mileage increase unless you drive like grandma.

I run 265's. After installing the Banks six-gun my normal commute MPG went from 16.5 to 17 and my highway MPG (running 75 plus) went from 18.5 to 19.5ish. I can get 20-21 if I run under 65MPG.


Best way to increase your MPG is a light foot and highway speeds of 60-65 but there's no fun in that.....http://www.dieselplace.com/forum/smileys/HiHi.gif

Fred G,


Do you have the Speed Loader with you 6-gun? I assume the SL in your sig means Speed Loader... what about exhaust... sorry I am new to this http://www.dieselplace.com/forum/smileys/Ermm.gif


Regardless, how do you like the 6-gun in all aspects (any troubles)?

Bullydog Power Pup Downloader, works great on 70 hp setting, 3.8 mpg increase and low egt's. Be very careful when it comes to your EGT'S!!

I am running a special on Duramax exhausts right now and if you'd like an Exhaust and intake or even a Edge box as well, I can work you a great deal.


Check out my Chevy/GM page and give me a call if you have any questions
http://www.blackclouddiesel.com/GM/gmhome.htm

I have the Attitude and Predator and with either of these I have not seen an Increase in mileage. So do not expect to see a mileage increase unless you drive like grandma.



I do drive like a grandma... I "try" to keep it under 65 mph and I do see 20 mpg using the edge product set on level 1!http://www.dieselplace.com/forum/smileys/Big Smile.gif This is outstanding fuel mileage for a truck.http://www.dieselplace.com/forum/smileys/Big Smile.gif