04 Chevy with Superchips 2815

[Primed67]

I have an 04 Chevy 1/2 ton 4-wd crew cab with the 5.3 liter. Does anyone have any experiences with the new superchips 2815 programmer. I drive around 1,000 miles a week so i need to get the best mileage possible. I'm not worried about boosting power because i have the 67 for that, i need to get more mileage out of it. I just wanted to see if anyone was using one and what kind of fuel mileage improvement they got? Thanks for any help!!