MPGe

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by Jonny Zero, Sep 8, 2014.

  1. Jonny Zero

    Jonny Zero Giggidy

    Joined:
    Jun 22, 2012
    1,388
    350
    0
    Location:
    Austin, TX
    Vehicle:
    2012 Prius
    Model:
    Five
    I have a question about MPGe. Is the KWH measured at the meter, or coming out of the battery? In other words, does it account for the conversion loss when charging the battery?
     
  2. rxlawdude

    rxlawdude Active Member

    Joined:
    Mar 31, 2011
    701
    219
    0
    Location:
    So Calif
    Vehicle:
    2015 Tesla Model S
    This topic has been covered, but most here are sure it's the latter. My [casual, non-scientifically verified] observation seems more consistent with the AC supply draw.
     
  3. Jeff N

    Jeff N The answer is 0042

    Joined:
    Oct 23, 2010
    2,382
    1,302
    0
    Location:
    California, USA
    Vehicle:
    2011 Chevy Volt
    EPA's MPGe calculations are based on electricity as measured at the wall socket or utility meter.
     
    CaliforniaBear likes this.
  4. Rhodrons

    Rhodrons New Member

    Joined:
    Jul 13, 2014
    20
    3
    0
    Location:
    Chessington, Surrey
    Vehicle:
    2014 Prius Plug-in
    Model:
    N/A
    What interests me more than MPGe is pence/mile travelled because that is what I pay for! It's ok for you transatlantic cousins who have fuel at $1.10/litre but over this side of the pond it costs the equivalent of more like $2+/litre so you can see what the incentives to drive electrically as much as possible are. For interest my fuel price last week was $2.10/litre and my marginal electricity cost is 17.7cents/kWh.
     
  5. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,174
    287
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    I agree its kWh from the electric company. When you fill your car with gas and happen to spill some (naughty), or some is sucked back up because you try to over fill, you still have to pay for the undelivered gas.
     
  6. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    10,997
    3,439
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    2006 Prius
    ...wow that's a fairly cheap electric cost for you considering everything is more expensive over there. My cost is 12 cents but some places like Ca and NY are closer to 25 cents which is closer to break even gaso/electrons.
     
  7. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,174
    287
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    California can be as low as $0.10/kWh on the PG&E EV time of use rate. With solar panels to reduce your total kWh, other rate schedules can provide costs under $0.15/kWh.
     
  8. usbseawolf2000

    usbseawolf2000 HSD PhD

    Joined:
    Sep 22, 2004
    14,487
    2,983
    0
    Location:
    Fort Lee, NJ
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I am paying 18.5 cents per kWh. Gas price around here is some of the lowest in the nation. Yesterday, I saw $3.09 for regular gas.

    Even then, electricity is 2/3 the cost of gas per mile.
     
  9. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    10,997
    3,439
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    2006 Prius
    ...that's amazing low gaso cost considering NJ is the more expensive Reformulated Gasoline.
    Obvioulsy the NJ ban on self-serve stations does not seem to impact cost either.

    Good deal! I should not have implied everyone paying ~25 cents in Ca.
     
    #9 wjtracy, Sep 9, 2014
    Last edited: Sep 9, 2014
  10. miscrms

    miscrms Plug Envious Member

    Joined:
    Aug 21, 2007
    2,076
    520
    5
    Location:
    Phoenix, AZ
    Vehicle:
    2005 Prius
    Hadn't seen this before, but could be useful for estimating costs:
    PHEV Fuel Economy
     
    usbseawolf2000 and Jonny Zero like this.
  11. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,174
    287
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    It seems to be reasonably accurate. I used the detailed driving option.
     
  12. usbseawolf2000

    usbseawolf2000 HSD PhD

    Joined:
    Sep 22, 2004
    14,487
    2,983
    0
    Location:
    Fort Lee, NJ
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I used the simple driving form.

    17 miles for typical day and 10,000 miles annual. 19 cents per kWh with 110V charging. $3.20 for regular gas and $3.5 for premium gas.

    BMW i3 REX = $624
    Accord PHEV = $629
    PiP = $630
    Regular Prius = $640 (100% gas @50 MPG)
    Volt = $730
    C-Max Energi = $762
     
  13. mindmachine

    mindmachine Member

    Joined:
    Jul 11, 2009
    394
    79
    7
    Location:
    Ohio
    Vehicle:
    2014 Prius Plug-in
    Model:
    Plug-in Advanced
    Using 110 volt charging is not a valid assumption if you own a BMW i3. Using 220 volt changes the cost to $556/yr. I can't imagine anyone buying a car that takes 19 hrs to charge on 110 volts being too frugal not to get a 220 volt EVSE.
    I have a 2014 Prius pip and a i3 Rex and i pay 12 cents/kwh. My i3 cost is $352 for 10000 miles. Actually I am doing even better than that as I am getting closer to 4.4 miles /kwh as opposed to the 3.4 miles/kwh used by the calculator. Based on my data I am looking at $274 for 10000 miles in my i3.
     
  14. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    10,997
    3,439
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    2006 Prius
    Interesting MindMachine can you briefly say why 220 v is so much cheaper and how much time does it cut off on the 19-hrs benchmark?
     
  15. usbseawolf2000

    usbseawolf2000 HSD PhD

    Joined:
    Sep 22, 2004
    14,487
    2,983
    0
    Location:
    Fort Lee, NJ
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    Good point. The calculator takes account of charging time and resulted in using less gas with L2 charger. That's why the difference is significant.

    BMW should bundle L2 charger with the car.

    If I use NJ fuel cost (18.5 cents / $3.2 gallon) with my first year of ownership data (in NY), PiP would cost me $528 to drive 10,000 miles. I got 75 MPGe in the first year with 44% EV ratio. I added 15% charging loss to the kWh reported by the car.

    Does your 12 cents/kWh includes both the supply and distribution, etc charges? Also, 4.4 miles / kWh includes charging loss?
     
  16. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

    Joined:
    Nov 27, 2005
    2,643
    1,072
    0
    Location:
    Roseville, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    My electric cost varies from $0.05/kwh at tier 1 off peak to about $0.47/kwh at tier 3 peak (San Francisco Bay area, California). I don't charge during tier 3 peak.:)
     
  17. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,174
    287
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    Yes. However, the kWh you use off-peak may add to your total kWh and "push" some number of kWh into tier 3 from tier 2 and into tier 2 from tier 1. If you stay within the baseline every month this effect doesn't happen. How does this happen? When your total exceeds the baseline (tier 1) amount all subsequent kWh are charged at the tier 2 rate, and the same for when your total exceeds tier 2. Now if that happens on the last day of the month it doesn't make much difference to the total but if it happens mid-month you could be effectively being charged higher tier rates for your off-peak charging due to the "push effect".

    If you have a solar installation there is a good chance you can stay within the baseline for most months. In 18 months I have only had a few kWh in tier 2 during the last 10 days of one month.
     
  18. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

    Joined:
    Nov 27, 2005
    2,643
    1,072
    0
    Location:
    Roseville, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    My summer electric bills tend to be about $80/mo, even with charging my PiP every night. My understanding is that with an electric bill less than $100/month, that one cannot really justify solar. And the thought of installers stomping around on my clay tile roof is painful.
     
  19. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

    Joined:
    Oct 9, 2012
    1,174
    287
    0
    Location:
    Northern California
    Vehicle:
    2012 Prius
    Model:
    Plug-in Base
    We live in the Sacramento area so lots of A/C in the summer also lots of sun. Our annual total electric bill was $1200 before adding solar but without the PiP. The first full year with solar it was $232 including charging the PiP at average of 3.1 kWh per day (that is, sometimes charging more than once a day and not using all the charge every trip). The solar installation on our tile roof cost $12,000 so I see about an 8% return on investment. Of course there was more sun in the past year than would be normal so I expect the total bill will be higher some years.
     
  20. mindmachine

    mindmachine Member

    Joined:
    Jul 11, 2009
    394
    79
    7
    Location:
    Ohio
    Vehicle:
    2014 Prius Plug-in
    Model:
    Plug-in Advanced
    Yes my total cost actually varies do to add on charges that are not proportional, but essentially my Total electric cost is about 12.5 cents per kwh.
     
Loading...