MrDRMorgan
Posts: 931
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: List your miles and MPGe

Fri Mar 23, 2018 7:11 am

Here is a link where you can find the gallon-gasoline equivalent in kWh for different blends of gasoline:
https://en.wikipedia.org/wiki/Gasoline_ ... ent_tables.

Multiply your trip meter's mi/kWh value by the GGE value from the table and then multiply that value by 80% (0.80) [L2 charging efficiency] to get the MPGe value for your vehicle. Unless you manually reset the trip meter, it will keep a running mi/kWh average starting from the last time it was reset. I reset the trip meter after every full charge. For the last 1000 miles [Dec - Mar in Central California] I averaged 5.2 mi/kWh. Using a winter blend value of 32.97 kWh/gal and 80% L2 charging efficiency, my MPGe is 137. Use the EPA value of 33.7 kWh/gal if you want to make a comparison to the EPA estimate on a window sticker.

The March 1, 2018 report I received from OnStar shows my MPGe to be 134 for the previous month [February].
Last edited by MrDRMorgan on Fri Mar 23, 2018 9:08 am, edited 1 time in total.

Planerench
Posts: 110
Joined: Mon Oct 02, 2017 5:20 pm
Location: Idaho

Re: List your miles and MPGe

Fri Mar 23, 2018 9:04 am

PhilPen wrote:If your primary concern is environmentalist you will want to compare your EV to gasoline in terms of relative CO2 production.
When you burn one gallon of pure gasoline you get 19.64 pounds of carbon dioxide (CO2) (from E10, gas containing 10% ethanol, you get 18.95 pounds of CO2).
If you go to https://oaspub.epa.gov/powpro/ept_pack.charts you can get a figure for how clean or otherwise your electricity generation is by entering your zip code and electricity supplier.
In my area of CT using UI for electricity the CO2 emission rate is given as 571 pounds of CO2 per MWh or 0.571 lbs/Kwh (a relatively clean state). Thus for the equivalent CO2 as produced by burning one gallon of pure gasoline I'll get 19.64/0.571 = 34.4 KWh (for E10 its 33.2 KWh).
Multiplying this value by my charger efficiency, I’ll use 87.8 % as my L2 charger efficiency ( https://www.veic.org/docs/Transportatio ... Report.pdf ). Thus for the same quantity of CO2 released by burning one gallon of gas I’ll get 30.2 KWh in my battery. Since my current average is 4.1miles/KWh (it’s started going up with the warmer weather) I get a pollution mpge of 124.

Efficiency losses during electricity distribution via the grid would already have been taken into account if the government published figure for CO2 lbs/Kwh is based upon what the customer receives, which seems logical. However, there are additional losses incurred with gasoline that I have ignored, so gasoline is in actuality dirtier than the 19-20 lbs of CO2 you get per gallon by simply burning it, because it takes significant energy to refine and distribute the gasoline… and I’ve ignored this. My ultimate aim would be to use home solar power for my electricity source then I’d generate no net CO2 from driving. Unfortunately I live in a very shady area so I’m not the best candidate for this (I don’t want to cut down multiple large trees to go solar).
I am within round-trip driving distance of the hydroelectric plant that supplies my power!

MrDRMorgan
Posts: 931
Joined: Wed Oct 30, 2013 7:27 am
Location: Manteca, California

Re: List your miles and MPGe

Fri Mar 23, 2018 9:20 am

PhilPen wrote:If your primary concern is environmentalist you will want to compare your EV to gasoline in terms of relative CO2 production.
When you burn one gallon of pure gasoline you get 19.64 pounds of carbon dioxide (CO2) (from E10, gas containing 10% ethanol, you get 18.95 pounds of CO2).
If you go to https://oaspub.epa.gov/powpro/ept_pack.charts you can get a figure for how clean or otherwise your electricity generation is by entering your zip code and electricity supplier.
In my area of CT using UI for electricity the CO2 emission rate is given as 571 pounds of CO2 per MWh or 0.571 lbs/Kwh (a relatively clean state). Thus for the equivalent CO2 as produced by burning one gallon of pure gasoline I'll get 19.64/0.571 = 34.4 KWh (for E10 its 33.2 KWh).
Multiplying this value by my charger efficiency, I’ll use 87.8 % as my L2 charger efficiency ( https://www.veic.org/docs/Transportatio ... Report.pdf ). Thus for the same quantity of CO2 released by burning one gallon of gas I’ll get 30.2 KWh in my battery. Since my current average is 4.1miles/KWh (it’s started going up with the warmer weather) I get a pollution mpge of 124.

Efficiency losses during electricity distribution via the grid would already have been taken into account if the government published figure for CO2 lbs/Kwh is based upon what the customer receives, which seems logical. However, there are additional losses incurred with gasoline that I have ignored, so gasoline is in actuality dirtier than the 19-20 lbs of CO2 you get per gallon by simply burning it, because it takes significant energy to refine and distribute the gasoline… and I’ve ignored this. My ultimate aim would be to use home solar power for my electricity source then I’d generate no net CO2 from driving. Unfortunately I live in a very shady area so I’m not the best candidate for this (I don’t want to cut down multiple large trees to go solar).
Thanks for this posting. It provides great information so I printed the L1 and L2 Charging Efficiency report and I too will use 87.8% for my L2 EVSE.

TheLondonBroiler
Posts: 179
Joined: Tue Oct 31, 2017 6:25 am

Re: List your miles and MPGe

Fri Mar 23, 2018 9:40 am

Chris101 wrote:How are you guys seeing the MPGe anyway?
I'm curious to know this too. When I log onto the OnStar full website, it redirects me to the MyChevrolet full site, which shows a "My Charging and efficiency status section," which tells me that my vehicle isn't associated with an onstar account.......
Chris101 wrote:Yesterday I drove very conservative in L, DRL off never going above 56mph on the highway with cruise set ON and STILL only 3.7kwh per mile efficiency displayed after a 60+ mile jaunt. (It was 42 degrees at the time)
Was this round trip or one way with an elevation increase? Wind direction, tire pressure, road condition, climate control setting, acceleration/managing hills, and other factors I'm sure, all come into play.

I didn't leave work until 01:40 this morning, and out of curiosity, I wanted to see what I could manage on my way back home. Fortunately, while there is a interstate I usually take to work, there is a 4 lane highway with 35-55mph speeds that runs parallel. With a heavy hooded coat, leather gloves, and my seat heater as my only friend, I drove 31.75 miles in 37-42°F (no climate control was used), my home is 50ft higher in elevation than my work place, there was a headwind of ~10mph, and I managed 6.2mi/kw efficiency for the trip. My tires are inflated 41psi cold, which is contrary to both GM and tire manufacturer recommendations. Also, because I was driving during the wee hours and encountered few other cars, I
decelerated up hills (I live in the foot hills of the Appalachian mountains) and I would estimate my average trip speed was right around 35mph. I would not drive in this fashion with any amount of traffic, unless it meant not getting to my destination otherwise.
2015 Spark EV w/ DCFC 46,XXX miles
Purchased 1/20/18 w/ 16,5XX miles
2019 Bolt EV w/ DCFC 6,XXX miles
Purchased 3/16/19 w/ 87 miles

SparkE
Posts: 306
Joined: Tue Sep 06, 2016 1:18 am

Re: List your miles and MPGe

Fri Mar 23, 2018 3:23 pm

MPGe :

33.7 kilowatt-hours of electricity is equivalent to one gallon of gasoline.

How many miles can you vehicle travel on 33.7 kWh?

If you get 4 miles per kWh, then you are getting 4*33.7=134.8 MPGe.

If you get 4.5 miles per kWh, then you are getting 4.5*33.7=151.65 MPGe.

If you get 5 miles per kWh, then you are getting 5*33.7=168.5 MPGe.

Chris101
Posts: 91
Joined: Thu Jan 18, 2018 11:37 am

Re: List your miles and MPGe

Sat Mar 24, 2018 3:03 am

Regarding my 60 mile jaunt. I showed maximum efficiency (all lit up to the best mileage possible/most efficient) on my 30 miles going THERE.

There was no winds that day (maybe 4-5mph tops) -- and no wind chill factor either

ON the way home I saw less efficiency on the lights but still above half. My thought was battery conditioning happening on my way home so I even turned off the radio for that ride home.

NORTON
Posts: 1210
Joined: Fri May 01, 2015 5:52 am
Location: KC,MO

Re: List your miles and MPGe

Sat Mar 24, 2018 8:00 am

Chris101 wrote:.... My thought was battery conditioning happening on my way home so I even turned off the radio for that ride home.
If you don't plug in at work and it was a cold day, you could have 'battery conditioning' happen on the return leg ,, but then that would be displayed on the usage page.
Used '14 2LT w/ DCFC.
+67 K miles. Mostly free electrons! Only one LONG visit to the shop....
GM needs Modern Troubleshooting tools for Modern EV's.

Chris101
Posts: 91
Joined: Thu Jan 18, 2018 11:37 am

Re: List your miles and MPGe

Sat Mar 24, 2018 5:09 pm

NORTON wrote:
Chris101 wrote:.... My thought was battery conditioning happening on my way home so I even turned off the radio for that ride home.
If you don't plug in at work and it was a cold day, you could have 'battery conditioning' happen on the return leg ,, but then that would be displayed on the usage page.

I was driving so bringing up a usage page was not on my mind.

SparkE
Posts: 306
Joined: Tue Sep 06, 2016 1:18 am

Re: List your miles and MPGe

Sun Mar 25, 2018 10:45 am

Chris101 wrote:
NORTON wrote:
Chris101 wrote:.... My thought was battery conditioning happening on my way home so I even turned off the radio for that ride home.
If you don't plug in at work and it was a cold day, you could have 'battery conditioning' happen on the return leg ,, but then that would be displayed on the usage page.

I was driving so bringing up a usage page was not on my mind.
It will remain on the "usage page" until your next charge to 'full battery' (when everything is reset).

agdodgerfan
Posts: 51
Joined: Thu Jul 24, 2014 8:17 pm

Re: List your miles and MPGe

Wed May 23, 2018 1:43 pm

Just wanted to post an update. I am now at 96,500 miles. Range usually says about 66 - 70 miles when I am fully charged. I am addicted to the Level 3 option. Mainly because I drive a lot. When I can just top off at home on level one I do.

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