well, i've checked every tank since i got her, and im repeatidly getting 17.5 18 mix low speed and highway speed.(but never over 60) occasionally dragging boat behind me. i was questioning wether this was accurate for the 4.6 or not?

 

07 screw 5.5' box 4x4 3.55 gears 265/70/17 BFG AT's. 17 average mostly back and forth to work 10 miles each way.

 

Magnaflow did nothing to help my mileage. An intake MIGHT help. Really, I find that my exhaust makes more noise than horsepower or economy. It's cool, but make sure you understand the implications of buying a cat-back.

 

I'm getting a whopping 12 mpg in nothing but city driving. But I don't drive her everyday. Only been through 3/4 of a tank in 2 months! But I get 24 in my 5-speed!!!

 

My usual is 13-16 with 50/50 hwy/city. Depends on traffic, temp, time of year, etc... All hwy I get 15-22 depending on speed and wind. Towing get 10-14 again depending on load, speed and wind. the 10 was pulling 8K pounds across country in former screw. the 22 was cruise set at 70 with a 15 mph tail wind and gate down (only b'c I had some long cargo)...

Truck is pretty consistent with those numbers. Only mod is a spacer lift and a Superchips tuner with 87 tune.

 

I follow my brother towing a 38ft trailer so never over 60 MPH very slow take offs 80% Hwy from MD to PA up and down Hills (mountains) 21 MPG , driving normal taking this route i would get 15 MPG driving 60 to 80 MPH