I just drove my 2019 with eTorque Hemi and 3.21 gears to Baltimore and back (I live in Cary, NC). Only put around 750 miles on it the whole trip (including driving around the DC area). But I was averaging 20mpg on the highway and 15.2mpg in town. I regularly get 14mpg at home and have just over 3800 miles on the Ram now.
So, I am not really going to complain about the mileage. And I too was running 90 to 92mph most of the trip on the highway.
My other vehicle (a 2018 Chevrolet Camaro ZL1 with a 6.2L supercharged smallblock) only gets me around 13mpg on average. Although, the month before I got the RAM, I did take the Camaro to Charleston, SC and back. Got 22mpg on the highway. I even eclipsed triple digits a few times on I-95 and still got fantastic gas mileage.
Anyway, I am pleased with the mileage. Not up to dealer claims, but still better than my 2014 Silverado got me.
Here is a pick of my ZL1. The "other woman" in my life. Just ask my wife...