In a way, it's good that it's your first diesel: if you had gone from a 5.9 Cummins to a 6.7 Cummins, you might be having mileage shock, as the 5.9 got better mileage but the 6.7 is more motor, torque, and HP right out of the box, so you'll get used to that mileage right from the get-go. Plus the factory exhaust/jake brake is pretty awesome! Congrats!
When you get a chance, check out this site and it's forums:
Dodge Diesel - Diesel Truck Resource - Cummins - Home
Similar to the FR forums, specialized to Cummins Dodge, and very helpful people. Lots of answers to lots of questions about our trucks.
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