Cruising range can also be distorted by how you end each refulling event. I have found that the computer ignores fuel "topoff" above a certain point which is not necessarily the gas pump shutoff point, and as a result, the first part of the range calculation tends to read low because the tank is still "full" as far as the electronics are concerned. It gradually adjusts itself once the tank level is in the sense range of the system.

The same situation initially ignores any "topping off" after the first fuel shutoff. I usually do an additional topoff after the first shutoff to a point that I have predetermined for the fuel nozzle in order to have a consistent tank full quantity.

It is the ignorant among us that will eventually destroy us all.