Tesla knows the shape of the curve, location of the median, standard deviation, etc. etc. Why not publish EPA and median with a description of how the median driver drives since Tesla knows their average speed, mix of freeway versus local, etc.?
If M3 owners get 13% less than the EPA number, there is going to be an uproar. It's in Tesla's interest to be as transparent as possible.
We know the S90D EPA number is 273 W/mi. I'll start a poll and see what the curve looks like. We'll let the numbers do the talking.
Here is the poll.
There is the projected range on the energy graph. It's easy to compare that to the rated range. I don't use it much anymore because of the trip graph, but it's still there.
I don't believe it really matters what value is found for the median. Half of the people are going to be above, and the other half below. Also because there are more drivers in California, the results are going to be weighted to California driving, so the median found is likely to be inaccurate if you live elsewhere. (Might be higher or lower.)
Bear in mind the EPA number was never intended to indicate real world values--even though people use it that way. It was designed to be a tool for comparing cars before purchase. The correct way, in my opinion, to use it is:
A. Find the EPA number for your current car.
B. Get the actual number for your present car from your logbook.
C. Divide B by A.
D. Find the EPA number for the car you want to purchase.
E. Multiply D by C to get the number you can expect from the new car.
(Note: This only works if the EPA doesn't fiddle with the formula.)
F. Once you purchase a car, ignore the EPA number.
Example:
A = 30
B = 25
C = 25 / 30 = 0.83
D = 60
E = 60 * 0.83 = 50
When the Prius came out, a lot of folks complained it didn't get the EPA numbers--at the time the EPA used the Two Cycle program. I suspect that for many purchasers (and probably all the complainers) their Prius was the first time they actually knew what they were getting. Because most folks don't keep a logbook, they just assume they are getting the EPA numbers. That thinking is reinforced because the times they do check is typically on a trip where a tank of gas is used in less than a day. Typically highway driving is closer to EPA than commute driving or winter driving.
And there's one more thing. New Tesla drivers are likely to use full acceleration more frequently than those who have had the car for awhile. The 90 kWh battery is new so there are a larger proportion of new owners which will raise the median Wh/mi making the results seem further from the EPA numbers than they are.
And finally, if you don't keep the tire pressures up, Wh/mi will increase.
