Thanks to the 62 people who filled out my survey trying to understand Rated Range. The long detailed analysis is available here including the graphs:
For purpose of discussion, the executive summary is the following:
Rated Range Varies for the Majority of Cars in the Following Bands:
175-195 for 60kWh Batteries
220-245 for 85kWh Batteries
The rated range appears to have no correlation between energy used over long periods of travel.
The rated range appears to have no correlation between miles driven. Since the cars are so new there is unlikely to be much battery degradation yet.
I think this survey almost asks more questions than it answered. There is clearly not a clear correlation between long term driving habits and rated range. Perhaps immediate short term driving habits? Perhaps the car simply cannot measure the amount of energy in the battery very accurately? How accurate, reliable and useful is this rated range number? Why is there so much variation in the rated range number in the Model S?
What I would personally like to see is an accurate consisted rated range that I could understand and also a simple energy measurement. I would like to see a gauge that simply said 55kWh left in my battery. I would find this more straightforward. I can do the simple math in my head to convert that to "can I drive to X without recharging"
I am also wondering if part of the problem with giving these accurate numbers is that historically cars do not give you accurate measurements of remaining fuel. All of the cars I have owned have had crude analog gauges or digital readouts that were stepped scales and not a simple readout "12.1" gallons left.
I am looking forward to any comments on this survey and if there are any suggestions on other things to look at.