2018 Ram fuel milage questions

I have a 2017 standard cab 3500 with a 6.4 and 4.10 gears, it is a complete pig on fuel, averages 10 mpg.
I bought the truck new almost a year ago, and just do not drive it, it has 3,000 miles on it now.
The fuel mileage is horrible, I just drive my old jeep, and just use the truck when I need to tow or haul something, even then most of the time I use my old 78 powerwagon, at least it gets 14.5 mpg.