on an 05 LLY level 1 is for milage but i heard level 4 does better.

what level gets you your best fuel economy

this is the edge juice with attitude.

Moved to 2nd Gen Electronics

I seem to get my best highway mileage on level 5/5, but for most mixed driving, level 3/3 does better. I don't see much of a benefit to level 1.

For my trans sake, I don't use above level 3 unless I know I can restrain myself.

Subscribed

just search a little.... tons of threads already about this.

http://www.dieselplace.com/forum/showthread.php?t=49762

good luck!