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Discussion Starter · #1 ·
I have been keeping track for 4 years now the kWh / 100 miles from the OnStar monthly diagnostic emails. I have charted this using the monthly average temperature as reported by the Capital Weather Gang from the Washington Post.

Since I rarely (very rarely) use climate control, the differences can solely be attributed to changes in outside temperature. I have gotten a bit more efficient in my driving starting around year #3. This can be attributed to me raising my tire PSI to 50 and more use of neutral in my driving. There is a drop-off in year #4 due to having to replace my worn out tires.

I have included two versions of the charts, one a line chart with a primary and secondary axis for temperate and kWh/100 miles and scatter chart with temperature on the X-Axis and kWh/100 miles on the Y axis. Finally, for a sanity check I have added yearly averages for temperature and kWh/100 miles.





 

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Very interesting. From the scatter graph it looks like there's a "knee" on the curve at temperatures around 50F - above that there's not a lot of change in efficiency and below that efficiency starts to drop more significantly.

Useful info, thanks for taking the time to post!
 

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Thanks for sharing your data. It appears that year 3 provided the best mileage efficiency. Maybe I'm reading too much into that but still very interesting data.
 

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Discussion Starter · #4 ·
Thanks for sharing your data. It appears that year 3 provided the best mileage efficiency. Maybe I'm reading too much into that but still very interesting data.
It is called new tires, I replaced them at 55K miles in August 2014! Also, year #4 was a little colder.
 

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Ari, are you seeing any battery degradation now?
 

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Hmm, I can't view your graphs for some reason but your experience seems to match my own.

I am curious though, do you remember where the graph of the
various battery temperatures and the cooresponding heater/ car behavior was?

I remember a nice chart listing the different battery temperatures, states and behaviors when I first joined here.

I am also curious which fuse is related to the battery heater.

I am tempted to run a little experiment of my own but I always have tracked gas use at different temperatures over my rather stable identical trip and oddly the gas efficiency tracks EV efficiency well.

Oh well
 

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Very interesting. From the scatter graph it looks like there's a "knee" on the curve at temperatures around 50F - above that there's not a lot of change in efficiency and below that efficiency starts to drop more significantly.

Useful info, thanks for taking the time to post!
That would be around where battery heat starts to come into play. As Ari doesn't really use heat, battery heater is going to be his largest energy draw at cold temps. Far greater than drop in efficiency from colder tires, etc
 

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Thanks for sharing, Ari!

Based on this data, the infrequency of sub 50F temperatures for me explains my consistently low kWh/100 mile numbers.
 
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