edatoakrun wrote:I have sent and received a few Emails RE the history behind LEAF 0356 and the several capacity and range tests linked on the first page of this thread.
One thing I'd like to see them do is to also note down the Leaf instrumentation values.
- m/kWh on the dash
- miles drives on the dash
This will give us some idea about the difference between what they are reporting what Leaf reports. For these numbers to be useful, we need this comparison. So, it would be great if you can suggest this to them in your future emails.
I really doubt that data would be useful, since IMO, all evidence shows that the error in m/kWh dash/NAV screen readings, the Carwings kWh reports, and the gid meter and app reported kWh use vary greatly from LEAF to LEAF, and in individual LEAFs over time.
What would be very useful, IMO, is to see if all these sources reflected a common (or very similar, as seems to be the case for my LEAF) kWh use report error in individual LEAFs, during a single driving efficiency test.
As I replied to you ~2 months ago, on the previous page of this thread, The DOE m/kWh test data should allow each of us to determine the accuracy of our LEAF's energy consumption Data from a test at any one of the three constant speeds.
Why don't you give it a try?
Since no one has posted any actual test results here, maybe what I wrote below about my LEAF was not clear enough as a suggestion:
...What I ultimately want to find out is - how many miles can I go if I'm getting, say 5.0 m/kWh on the dash. That is a question these lab results don't answer.
Nor (in all likelihood) can they, without additional effort on your part.
I know the answer for my LEAF for 5.0 m/kWh on the nav screen
~81 miles from "100%" to VLBW, after recharging at ~75F, but that is only because I know that CarWings presently
reports ~16.2 kWh used between those SOC levels.
But I'm pretty sure the ~16.2 kWh number is incorrect for my LEAF, and I don't think there is any reason to expect it would be correct for your LEAF, or for any other.
So while knowing the kWh capacity reported by CarWings, which is used to display the m/kWh on the nav screen, and (with ~2.5% miles error) on the dash is invaluable for my trip planning, it could never tell me what my actual kWh use was without a reference test, showing accurate kWh use in a controlled constant speed range test.
And now, with these test results, I believe I just may have the data I need.
To restate this in general terms for all LEAFs:
1) First you have to determine the error if any or both individual factors in your dash or nav screen m/kWh readout.
Find the actual
miles of your test course, and the nominal
kWh your LEAF is reporting on your dash/ Nav screen.
Find the miles using an online source, such as Google maps.
Find both your LEAF's reported miles, and reported nominal kWh use, as reported from Carwings.
Since these two factors are only reported separately on CarWings, I am unaware of any way a LEAF driver who does not have CarWings, or who refuses to use it, can determine the accuracy or errors in the Dash/Nav screen m/kWh displays.
In my own and many other 2011 and 2012 LEAFs with stock tires, the nav screen reports (correct) odometer miles/nominal kWh, and the dash reports (~2.5% lower) CarWings miles driven
/nominal kWh, but check for yourself!
2) Now, conduct a kWh consumption test over a fixed distance at one of the constant speeds from the DOE tests.
There is no requirement, IMO, to begin precisely at 100% (which would only be possible if you charged at, or towed your LEAF to, the start of the route) or run all the way to "turtle", though the greatest discharge will give you the best sample, and the one closest to the "100%" to past-turtle SOC range that the DOE used.
The devil is in the details, of course.
The DOE has a a traffic-free and near-level test track, can choose a test date with low wind conditions, and in every other way comply with the ~30 pages of test procedures (read them all before you try).
We have to make do with what is available, but near every LEAFer should be able to approximate "November in Phoenix" temps, during some season, and adjust their results for altitude, as required.
The greatest problem, for some (like me) is the lack of available level and constant-speed test routes near our homes.
Remember to consider both the ambient and battery temperatures of the DOE tests.
If you drive a long way to your test route, then immediately charge before the test (don't even consider a DC charge...)
you will probably heat the battery so much as to invalidate the efficiency results, just as you would invalidate your range test results by testing with a hot battery.
FYI, I did try a short and extremely rough
~45 mph test of my LEAF last June, and got ~5.3 m/kWh from my nav screen (which in my LEAF, accurately reflects the actual miles driven, and the identical nominal kWh use reported by my LEAF , on the dash, the nav screen and form CarWings).
That's ~9% higher than the 4.85 m/kWh from the DOE LEAF, #0356 driven at 45 mph.
The problem was, my best nearby opportunity being a very short route, ~22 miles round trip, and also over a gently rolling route requiring some regen to maintain speed, I really can't say whether that 5.3 m/kWh represented accuracy within a few percent, or more like within ~ten percent.
And the only DOE test reported so far is on a LEAF ~9 months from the factory with ~4k miles.
So, if there is a significant increase (or decrease) in LEAF efficiency over time, miles driven, or charge cycles, we will only know it when or if the DOE publishes more test results.
Meaning that, until it cools down a bit more, and I can attempt a much better controlled and longer test, and the DOE publishes data on a LEAF with mileage closer to my own, I really don't think I will know for sure whether my nav screen/ Dash, CarWings and my battery app (with only a few months data myself) are reporting a common kWh use report error, or not.