[Fraser Beatty]

Those sticker mpg calculations are grossly inflated over real-world driving. Those estimates are basically obtained in a lab under ideal conditions ie. perfect driving (no heavy acceleration), continuous speed, minimal wind/drag, smooth driving surface, no hills, etc. etc. I haven't driven a vehicle yet that met or exceeded it's stated mpg. Notice how they always say "UP TO x mpg" to cover themselves.

Dad just bought a 2011 Chevrolet Silverado 1500 2WD with the 4.8 and all the HD options, will post some mpg data once he starts keeping track of fuel mileage.