Thats about average. Alot of it depends on your driving habits. Highway, heavy foot, loaded, things like that. But 16 aint too bad. Think of what you would be getting ina gasser with the same weight.
Bed Cover, some additives, chips sometimes help. All of these might add a little, but if you get several of them you might get 1-4 mpg depending. Also be sure to change all of your fluids and filters on a regualr basis, that will also help. I am sure someone else will chime in here before too long if I missed anything. Oh, and
Glad to have ya here and congrats on the new ride. You will love it.