Desert Captain wrote:
enblethen wrote:
That isn't very good mileage.
I would start by slowing down almost 10 miles per hour.
I am guessing this is a 6.0 gas engine. 
Chevy 4500? is this like a Kodiak chassis? That would make it more like a Super C.
That is excellent, honest, real world mileage.  My E350 V-10 averages 9.5 (over the last 21,000 miles), cruising 60-62.  Sprinters that allegedly get 21 mpg... not so much.
:S
In the interest of full disclosure... I just realized that the computer has a running total of gallons used, and I have never reset it.   So the math works out to 9.4 MPG over 7800 miles.  I'm a little disappointed that is was not roughly 10, but it does seem I'm always driving into a headwind!  :)