Volt - Top 10 MPGe

April 2013, 1225 total miles, 111MPGe, 99% EV, 0.63g CO2/m, $0.005/m, 41m/d

 

Good idea! We have enough Volt owners around here for at least a top 5 list....

I assume the 19% charging loss comes from the EPA estimates for the Volt, right? EPA said the 2011 Volt takes 12.9 kWh for a full charge but it wasn't stated whether this was at 120v, 240v, or some averaging of the two. I see somewhere between 11.5 and 12.0 for a full charge at 240v on my ChargePoint and OnStar results for a 2011 Volt (2013 MY has a slightly larger battery). A Volt with 10.3 kWh of usable charge that uses 12 kWh to recharge would have a charging overhead of slightly less than 15%.

OnStar results already account for charging overhead so only manual records based on the car's console display of used kWhs would need to be adjusted by an assumed charging overhead. In my experience, ChargePoint reports slightly less energy consumption than OnStar although it's been awhile since I compared charging records side-by-side.

This isn't realistic because, for reasons I don't understand, GM does not provide kWh figures to voltstats.net so they cannot know the actual electrical efficiency. Instead, volstats.net falls back on using the EPA estimated EV efficiency and those estimates are typically way too low for someone entering a "top 10" efficiency report. Realistically, drivers will likely have to get their data from OnStar or their own record keeping. F8L's actual MPGe is likely substantially higher.

I'll look at my records and submit my own entry this weekend.

 

Hmm onstar online reports for motst recent 30 days like below



Not necessarily going to be easy to get 1000 miles for me a month.. Maybe I can combine 2 30 days periods.
For the email reports they don't list kWh used.. (just kWh/100 miles.. which is a measure of efficiency not power)

 

Just to add to the confusion, there are 2 different OnStar efficiency screens.

The main one brought up when you click on the efficiency button has a fixed 30 day average display of information. It appears to be adjusted to account for charging overhead in my experience.

There is another display in a popup window when you click the efficiency "Details" button and that one let's you choose to average across different time ranges. That is the display that drinnovation posted above. That data does not appear to be adjusted for charging overhead in my experience.

In the doc's snapshot, it shows 138 kWhrs for 618 miles which is 223 Wh per mile and I'm guessing that should be around 250 Wh per mile when charging overhead is included.

You can also get a low-level record of each charging session and that data appears to include charging overhead and is consistent with the main efficiency screen if you average the detailed records together manually. At least that is my memory from having crunched these numbers in the past. The low-level records are also roughly consistent with the data reported by ChargePoint.

 

Ah, I now see that the 19% loss estimate came from this post over at the Prius Plugin top 10 MPGe thread.

Yes, that's about right for charging at 120v as indicated by the reference to measuring this with a kill-a-watt.

ChargePoint tells me that a full daytime (70-85F typically) charge of my 2011 Volt at 208-240v is usually 11.5-12.0 kWh (12-15% overhead) with a few 12.28 and 12.78 kWh charges in July last year. I'm guessing the higher numbers were due to especially hot weather causing the TMS system to cool the battery.

I'll try measuring full charging sessions overnight on OnStar and daytime on OnStar and ChargePoint at work this week (yes, we finally have 208v stations now at work!).

I'll report my results next weekend.

 

Yesterday I went 54 miles on EV, and had 4 left showing.. so 223 is possible. Been doing almost exclusivly the back way to work lately ;-)


Pretty sure the above include some charging overhead. It definitely did when they started reporting it. (when I checked). The daily charging data for the past 30 days totaled total the 138kWh shown above and included days of 11.95 on 7/15 and 11.78 on 6/30 (only days I came really close to empty). However those are less that 12.9 but also above 10.5. I'll have to get a kill-a-watt and test it again. I've not recallibrated since the onstar "restart" last october.


My voltstats page is
Volt Stats: Details for Volt #2011-03745 (DrInnovation)
Note the MPGe there is just assuming 93 for EV.. which I regularly blow away.

 

My voltstats page is:

Volt Stats: Details for Volt #2011-00042 (Jeff N)

 

I'm amazed there aren't more MPGe's over 95. Is it that much heavier than the Prius?

 

The data on voltstats treats MPG_CS (gas) as measured but presumes all miles on EV are 93MPGe. The only cars over 93 are 2 that had some work done recently and hence are reporting inconsistent data (which Mike will correct soon) -- note they also have crazy MPG_cs.. ( It happens when computer modules or batteres are replaced and the new ones report much lower usage than the past one).

As my reports show, voltstats is showing me at 92.55MPGe. when its really 117+MPG (or 130 depending what kWh screens I use to do the computation). ​

​

 

One useful thing to do at those voltstats pages is to click on the "Monthly Totals" tab to see the numbers for each month broken out separately.

 

I've decided to keep a running total for the next 1,000 miles which I will update in this post. OnStar data lags behind by a day or two so for the purposes of the running total I will assume my home overnight charging takes 12 kWh for a full charge and then correct it with actual data later. Other charging data comes from ChargePoint.

Monday, July 22
123.4 miles (82% EV)
26.37 kWh at 129 MPGe EV
.379 gallons gas at 59 mpg HV
106 combined MPGe

Tuesday, July 23
96.0 miles (100% EV)
23.00 kWh at 141 MPGe EV
141 MPGe

Wednesday, July 24
Working at home

Thursday, July 25
111.7 miles (86% EV)
23.95 kWh at 134.8 MPGe EV
.35 gallons gas at 45 mpg HV
105 combined MPGe

Friday, July 26
155.6 miles (82% EV)
33.20 kWh at 130 MPGe EV
.53 gallons gas at 52 mpg HV
103 combined MPGe

Saturday, July 27
118.1 miles (83% EV)
24.17 kWh at 137 MPGe EV
.42 gallons gas at 47 mpg HV
104 combined MPGe

Sunday, July 28
No driving.

Monday, July 29
113.30 miles (100% EV)
28.61 kWh at 133 MPGe

Tuesday, July 30
90.2 miles (100% EV)
22.97 kWh at 132 MPGe

Wednesday, July 31
90.3miles (100% EV)
22.87 kWh at 133 MPGe

Thursday, August 1
113.5 miles (91% EV)
26.19 kWh at 133 MPGe
.20 gallons gas at 50 mpg
116 combined MPGe


Running total
1012.0 miles (91% EV)
231.33 kWh at 133.50 MPGe EV
1.88 gallons gasoline at 51 mpg HV
538 combined MPG
116 combined MPGe


Notes: on July 22 & 26 the car switched to HV up in the hills which drove down my EV MPGe but also pushed up my HV mpg.

 

Here is my VoltStats info:
Volt Stats: Details for Volt #2011-03029 (Ampire)

 

I'm not up to 1,000 miles yet.

Need another week or so.

 

Volt Stats: Details for Volt #2012-00503 (ST's Volt)
Total Miles: 15556
EV Miles: 13641
% EV: 87.7
total gallons, gas: 47.3
MPG-CS: 40.48
total kwh from wall, estimated (Chargepoint): 30 kwh per 100 miles = 4092.3
MPGe, EV only = 112
MPGe, combined = 92.2

 

I have exact measurements reported from the wall charger at home and a few public Chargepoint stations. But I don't have records of:
- 1.5 months before getting the 240v charger
- about a half dozen uses of non-Chargepoint logged public chargers.
- plugging in at relative's home when traveling, maybe a dozen charges.

From spot checks of 2-month intervals where I only charged at home and have exact stats, I see usage as low as 28-29 kwh/100mi in warmer months, to a max of ~31 kwh/100mi in the cooler winter (never that cold in the bay area), so I figure my lifetime average is likely around 30. Probably slightly below 30.