Don't remember my 2018 JLUR's gas mileage being this bad when new. I got an average of 17-18 highway/city. I can do 55 on the highway in 2020 and get a reading of 12-13 MPG. When I drive like I normally would on the highway, 76-77, OMG, total crap, like 8-9 MPG. Should I be concerned that something's going on? I've only put about 350 miles on it.