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.

tonmiles.png

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.

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2 thoughts on “S, X and 3 Efficiencies

  1. Interesting… Since much of the car weight is it’s battery, you can interpret Ton-Miles / kWh not as “How much mass are you pushing along one mile”, but “How much mass you need to drive one mile”. Suddenly i3, 500e, Leaf (and Roadster!) are all very efficient… 🙂

  2. The Model 3’s battery efficiency is really remarkable. It set a new hypermiling record by travelling 606 miles in one full charge. Well, of course, an efficient driving practice was needed to achieve this feat but still, this established the Model 3 as one, if the not the best, long-range electric vehicle available commercially.

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