We live in the western US
I live in Utah Valley in the state of Utah. My wife and I are in NE Oregon for a few months. We own a 2017 Touring and have liked it until recently when the mileage went down about 10 MPG in a week. We had just had an oil change and we thought it was the wrong oil in the pan. We did everything we could think of to get the mileage back, with no success (including having the folks change the oil again). We even had the dealer check it out when we went in for one of many recalls. They said there was nothing wrong.
A couple of days ago it was topped off with regular gas again. We were going to check mileage the old school way with paper and pencil. We looked at the amount of gas used and the number of miles we went and figured that we were probably getting the mileage we expected, but it was not registering that much. When I topped it off it took 2.1 gallons and we had gone about 90 miles. I think the car was listening to us because... within a few blocks it started registering mileage the way it had before... In the mid 40s and above. About a 10 gallon increase. What's going on here!!!!? I'm about convinced that there is an error in the dash mileage instrument panel reading. Both in the actual instant and trip mileage. The miles to empty seems to have never changed much. Any ideas???? We will keep watching it to see if it changes again. Maybe this is the reason so many see a drop in mileage.