/S, X and 3 Efficiencies

S, X and 3 Efficiencies

Five years ago I looked at the efficiencies  of various electric vehicles and was very impressed with the progress Tesla made with the Model S versus the Roadster.  Several months ago, someone commented on my blog that I do the same analysis on the Model 3, but all the data was not yet available (Yes, I could have written this several months ago).

The data I generated in 2012 was a conversion from the MPGe issued by the EPA.  In the five years since, drivers are more comfortable thinking in pure electric terms such as Range and kWh (kilowatt-hours) of electricity.  So I did not use the EPA numbers at all in the current calculations.  The final numbers do differ but not in any significant way for this high level analysis.

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The efficiency analysis is quite simple.  First, how many miles of range can you go with a given battery pack.  So for the new Model 3 long range with 310 miles of range and a 74kWh battery, you can drive 4.19 Miles using 1 kWh.  All eight vehicles fall within a range of 2.95 to 4.38 miles per kWh.

To calculate efficiency of a vehicle, you need to also consider the weight of the car.  How much mass are you pushing along that one mile.  This number is listed in Ton-Miles / kWh.  Here again the English measuring system is very strange.  We normally think in pounds, and a ton is 2,000 pounds.  To calculate the efficiency measure of Ton-Miles / kWh, you simply multiply the weight of the car by the pervious range / energy number.

The “efficiency data” is quite interesting.  All the current Tesla vehicles fall within a very narrow range of 7.24 to 8.05 Ton-Miles / kWh.

Some of this data is a little tricky to calculate depending upon exact car options.   Tesla also did not report a lower weight for the Model 60, so the numbers are not exact but just give a general idea.   Surprisingly, the Model 3 is in the same efficiency range as the S and the X.  The Roadster, the BMW i3, Fiat 500e and the Nissan Leaf are much less efficient.  Perhaps the easy efficiency improvements were already implemented with the Model S.