In my experience, I can achieve parity between the two readings by driving at a constant 55MPH.
If I keep my energy consumption below that, the estimated range will be greater than the ideal range (by 5 to 10 miles). This happens on days when I drive only on local streets with 35MPH speed limits and few quick accelerations.
My regular commute includes a mix of highway (65MPH) and local roads, moderate changes of altitude and several traffic lights on roads with speeds around 50MPH. Under these conditions, my estimated range is shorter than ideal by 10 to 20 miles.