I just bought this 2500 van with the 6.0 engine & 373 rearend gears. What can I expect for mileage???? What can I do to get better mileage? Thanks Bernie

 

6 litre is supposed to be more efficient than the vortec 350 in my 2002, but you still will prob get around 14 to 16 if not loaded too much.
To get better mileage.....who knows. No matter how I drive mine I get the same.....
I guess you could upgrade the exhaust, and get low rolling resistance tires if they make those in a 10 ply....

 

I get 14-16 mpg with my 2012 3500. 40% local and 60% highway driving.