ok so i have a lowes cai,leveling kit,and a SC 3815 with gas saver tune and it says im getting 1.9 mpg....any opionis on what i screwed up??

 

Impossible, your truck would not run if you pumped that much gas into it. You need to manually calc your MPG.

 

Yeah, reset the overhead and try again.
Maybe up a long incline towing 8000lbs at WOT it might get 1.9mpg.

 

Assuming you are not towing a trailer, there is something wrong with your overhead calculator. Figure out by hand and see what you get.

 

how do i figure it out by hand??

 

Fill it absolutely full. Drive it. Fill it absolutely full (NOT to pump cutoff!!). Do the math. Forget the O/H console -- it's only a reference. They're not accurate enough to be meaningful.

 

Fill up your truck, set your trip meter to zero. Drive. Fill it up again. Divide the miles driven by gallons you put in on the second fill up. miles/gallons used = mpg

 

i'm getting bad mpg's with the new lift and bigger tires but nothing like that.

 

1.9 mpg would be less than 50 miles on a tank. i can certainly pull off 2 mpg, but either my tires, my transmisson, or my motor would be gone by the end of the day.

if it turns out you are actually getting 2 mpg, something is seriously wrong.

 

Hole in the tank?