Okay, first it is an '06 F-150 4.6L with K&N CAI, and Troyer tunes. The troyer tunes were first and it ran great (at sea level) when I moved up into high country it didn't run worth a hoot, so then I went and bought a CAI, and it helped a little but not enough. Anyone have any other tips.

 

New tunes that are made for the elevation you're at now would be my priority #1

 

Try living at 10,000 ft and working at 8500 ft. No power for me.

 

I live at 6000 ft and theres not much you can do. Don't waste your money on premium gas either, at altitude 85 octane works just fine. I just try to keep rpm's to under 2000 and drive with windows up all the time. Seem to get way better mileage in summer with ac on. I average about 13-14 combination driving, my best was 15.5.
I have CAI and edge, helped a little on power but not alot. Bigger tires, lift will also cut down on mileage. Usually the more power you have the less mileage you'll get.

 

Cough, cough, forced induction, cough.

 

Couldn't help but chime in...

As bad as my gas mileage is, I get way better mileage when I travel to higher elevations...

I live in the Sacramento area, about 200-400 ft above sea level...typical mileage is 10.8 to 12.8 mpg. When I travel to the Lake Tahoe/Reno area (5k-6k feet) my mileage increases to about 14 mpg. I know the roads aare different...

Regards!

 

I too get considerably better mileage at high altitude, but power is way down. I use 85 octane at altitude.

Pull the CAI and retune to stock and see if it makes a difference. You aren't going to get much power with a 4.6 without forced induction anyway.