I've monitored my mileage pretty closely since pulling the rig off the lot. I've always averaged right around 14.5, with a pretty close average of city/highway. Straight highway, around 16.7. I installed the K&N cold air kit (77-3065KP) and a Gibson cat-back performance exhaust (312700). They both install very cleanly, and look tough. As far as mph...roughly the same. Despite my hopes, and fears, mileage has stayed pretty much the same.

As far as the exhaust, it's a bit louder than I'd have hoped, and I'm currently looking for an insulation/sound proofing solution for the under-carriage area underneath the back hatch area, and inside the rear door to quelch some of the resonance I'm getting inside the cab. Any suggestions/success stories are certainly welcomed.

 

I have found with all vehicles that I have owned, CAI and exhaust made next to no difference in mileage.
Best performance mod=pcm tune IMO.

 

16 mpg city...hoping to bust the hwy epa by 2 mpg as well, i.e. 20 mpg.
I don't keep my foot in it, and drive like an old woman....
So I drive like Granny Clampett, but have extra coin in my wallet like Jed Clampett.
Have not driven pure hwy yet.

 

i have k & n air intake, , gibdon cat back extreme dual exhaust, and a pcm upgrade

i get about 17 mpg average all the time, combination street and highway

before all the work, the same ~maybe .2 - .3 mpg better now

but i do notice its a bit more spritely ! shifts quicker and seems quicker over all.