need better mpg

[kohlerfarms]

i have seen that some of you get 20+mpg with the duramax. i have an edge w/attuide open exhuast and can only get 13.5mpg. an help?

[The Neens]

Well, you're definitely in the right forum...Most of the high MPG claims you've heard about were obtained using EFI Live to tune the ECM...

[kohlerfarms]

can that be done if you have a chip hooked up like an edge box

[The Neens]

The Edge (harness box) "fools" the ECM, EFI Live reflashes your truck's ECM to the parameters you want to use...

[ScarabEpic22]

So no, you remove the Edge and sell it or put it on the shelf. Or use it as guages only.

[semperfidoordie]

Anyone have any good tips for changes to the tables to get 20+ MPG?

[LBZoom]

My personal opinion, is that most modifications to the fueling tables will hurt economy. Obviously more fuel sprayed is more fuel burned. The most helpful tables to modify are injection timing and boost pressure. I have adjusted my fuel pressure tables but haven't seen that it makes a whole lot of difference in economy, though I'm sure it would if I adjusted pulse to match it better.

My LBZ gets 22-23 highway at about 65-67mph. Use the timing calculator available on several forums. Also adjusting boost is beneficial while crusing bc too much boost simply creates what is known as a "pumping loss" aka extra friction due to increased cylinder temps with no gain in net power.