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I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Sun Apr 03, 2011 9:46 am
by evnow
Starting a new thread using Hill's idea.

Let us use this thread to document everyone's energy economy - and see how it compares with the EPA figures.

The main efficiency (or as they say, Energy Economy) figure from EPA is 34 KWh/100 miles or 2.9 miles/kwh. This kwh should be calculated at the wall - not carwings or what Leaf shows. This means, you should either have TED/kill-a-watt, separate meter or Blink to figure out the energy used by the car at the wall. You should also keep track of any charges done when not at home.

I suggest keeping track of and reporting the following figures. Copy the format below and replace with your actual numbers.

Code: Select all

Month : MMM-2011
a. x,xxx Miles
b. xxx kWh (Wall - Blink/Seprate meter/TED etc)
c. x.x Miles/kWh (Wall)
d. x.x Miles/kWh (Leaf)
e. x.x Miles/kWh (CarWings)
f. $xx.x
g. x.x Cents/Mile

Where,

a = Total Miles (from Leaf odometer)
b = kWh used (from the wall)
c = Miles / kWh (a/b from above)
d = Leaf Miles / kWh (weighted average of what Leaf reports, if you reset the number every day)
e = CarWings Miles / kWh
f = $ spent on Electricity for the car
g = Cents / Mile (f/a from above)

Here is my example for March.

Code: Select all

Month : March-2011
a. 565 Miles
b. 177 kWh (Wall - Blink)
c. 3.2 Miles/kWh (Wall)
d. 4.1 Miles/kWh (Leaf)
e. 4.9 Miles/kWh (CarWings)
f. $19.5
g. 3.4 Cents/Mile

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Sun Apr 03, 2011 10:14 am
by DaveinOlyWA
ok i bite. stats for March

a. 1118.1
b. 337
c. 3.3
d 4.45
e. 5.7
f. $35.29
g. 3.1

u can toss carwings out the window. i apparently forgot to accept the ok screen or something although i cant find but a single day where the mileage is off by any significant amount and that was 5.2 miles off on a 24 mile day. but everyday was inaccurate and the inaccuracies ranged from .2 for short days up to 2.2 miles on longer mileage days (50+ miles)... either way, Carwings listed me as doing 954 miles. that is a huge discrepancy

on the cost.... last time i filled Prius 8 days ago, it cost $37.60 to fill up for a 450 mile tank....

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Sun Apr 03, 2011 10:55 am
by evnow
Updated OP to make it easier to report.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Sun Apr 03, 2011 11:04 am
by ENIAC
Here' my data since LEAF delivery (1/13/2011).
a. 1796 Miles
b. 529 KWh (Wall)
c. 3.4 Miles / KWh (Wall)
d. 4.2 Miles / KWh (Leaf)
e. 5.8 Miles / KWh (CarWings)
f. $44.77
g. 2.5 Cents / Mile

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 2:47 am
by planet4ever
So how are you folks coming up with cost of electricity? I can't think of any way to do that unless:
  • You never charge away from home, and
  • You don't generate your own electricity (solar or wind), and
  • You have a completely flat electric rate - no tiers and no bulk rate reduction and no time of day or day of week variation.

My guess is that leaves out at least 90% of all LEAF owners at present.

If you do meet those conditions you can calculate the cost as a simple multiplication from item (b). The only real significance of the number is, then, that electric rates vary widely. This is largely out of our personal control and not useful to anyone with a different rate or rate structure.

That said, it would be interesting to see items (a) through (e) on a spreadsheet.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 7:19 am
by evnow
planet4ever wrote:So how are you folks coming up with cost of electricity? I can't think of any way to do that unless:

If you can figure out how much electricity you used and how much the electric bill was - calculating the cost of electricity isn't a problem. Either use marginal cost to get the cost of electricity or just get the average cents/kwh from the total bill and use that.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 7:28 am
by DeaneG
If you are in a steeply tiered rate structure (PG&E), marginal rates can be very different from average, as much as 4 or 5 to 1 at worst. Average rates are not really relevant in this case.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 7:31 am
by evnow
DeaneG wrote:If you are in a steeply tiered rate structure (PG&E), marginal rates can be very different from average, as much as 4 or 5 to 1 at worst. Average rates are not really relevant in this case.

That is a subjective discussion - depends on what you think is the marginal use of electricity at home. But yes, the rates can be quite different.

BTW, I'm using merginal rate - which is about 11 cents compared to the base rate of 8 cents.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 7:45 am
by hill
evnow wrote: Getting back to your original topic - let us see what what "beating the epa" in Leaf means.

The main efficiency (or as they say energy economy) figure from epa is 34 kwh/100 miles. This turns to 2.9 miles/kwh. This kwh should be calculated at the wall - not carwings or what the car shows. This means, you should either have TED/kill-a-watt, separate meter or Blink to figure out the energy used by the car at the waleport.

ok Evnow, so your personal calc's show 2.9 ... I'm curious - how much does that differ from what your dash displays.

Re: I Beat EPA's 2.9 Miles/KWh : Report Your Monthly Mileage

Posted: Mon Apr 04, 2011 7:50 am
by evnow
hill wrote:ok Evnow, so your personal calc's show 2.9 ... I'm curious - how much does that differ from what your dash displays.

Hmmm ... 34kwh/100 miles implies 100 miles/34kwh or 2.9miles/kwh. This is the EPA rating.

So, anything above this 2.9m/kwh is better than EPA i.e. you are beating EPA's mileage.