Good morning all - Glad to be here. I am a little concerned about the MPG on my 2019 2500 Big Horn 6.4L. I have only had it for a few days and have not done a longer drive than roughly 80 miles so I know I need to give it more time. I am only seeing 8 - 9.5 MPG. Truck has 38500 miles on it. All research shows an unloaded vehicle averaging about 15 MPG. Anything I should look at?