I currently run a 2001 Econoline 150 with a 4.6 for my business as a contractor and no matter what (city, highway, loaded or not) I get a consistent 12 MPG.

I am looking at a 2006 Express with the 4.8 what real world (preferably from contractors) fuel mileage can I expect?

 

you should get a little better, but most of it depends on your driving. A buddy of mine just got rid of a '99 E250 with the 4.6 and he was averaging about 16 fully loaded. (REALLY loaded)

Chevy's tend to do a little better anyway.

I get 16-17 with my '93 E-150, and my '06 Chevy 3500 6.0L gets about 13-14.