One of the most common comments I see on this forum is "why is Tesla misleading me about my vehicle's range". There are actually four "ranges" which are critical to consider, and the descriptions below may be helpful for those confused as to what "range" means.
Rated Range: The advertised range for the vehicle as determined by the EPA under defined and controlled operating and ambient conditions.
Projected Range: The remaining vehicle range shown on the energy chart screen determined by dividing the remaining usable battery capacity (watt-hours) by the average efficiency (wh/mi) over the chart’s displayed mileage range.
Estimated Range: The range displayed on the main screen green bar determined by dividing the remaining usable battery capacity (watt-hours) by the efficiency factor (wh/mi) established for the vehicle by the EPA (e.g. 220 wh/mi for the SR+). Note that when the energy chart efficiency (wh/mi) over the chart range displayed is equal to the efficiency factor established by the EPA, the "Projected Range" is equal to the "Estimated Range" at that time.
Actual Range: The actual range of the vehicle is equal to the Estimated Range divided by an “efficiency modification factor” (EMF). Where the operating and ambient conditions are identical to those under the EPA range/efficiency-determination testing, the EMF equals 1.0, and the Actual Range is equal to the Estimated Range. Where operating and ambient conditions are more favorable than those in the EPA test procedure (e.g. “hyper-miling”), the EMF is less than 1.0, and actual range will exceed estimated range. Where operating and ambient conditions are less favorable than those in the EPA test procedure, the EMF is greater than 1.0, and the actual range will be less than the estimated range. Such negative factors include: higher speeds, uphill driving, stop-and-go driving, rain/snow, head winds, tire pressure, etc.