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Track MPG and eMPG Independently?

Discussion in 'Prime Fuel Economy & EV Range' started by goinskiing, Jun 26, 2018.

  1. goinskiing

    goinskiing Active Member

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    Still getting used to all the extra bells and whistles on the Prime over the Gen 4, but I am curious if somewhere deep in the menus and stats if there is a place to see your eMPG and MPG separate for any given trip? I ask because I am curious of the hybrid MPG I'm getting after I am out of EV range, it seems like it's just an aggregate of the trip. Thanks!
     
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  2. Salamander_King

    Salamander_King Senior Member

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    No, AFAIK. In order to find out your HV MPG after EV, you will have to run out of EV range, then you have to reset Trip Meter.
     
  3. bisco

    bisco cookie crumbler

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    and it doesn't count miles when the engine is off, from what i understand, so your mpg would look low.
     
  4. mr88cet

    mr88cet Senior Member

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    Yeah, I wondered the same while I was waiting for our P.Prime to arrive (took several months to start selling them in TX). I think I even asked here, and no, no readily obvious way to do that.

    As it turns out, for my purposes at least, that turned out to be of little interest, because I’m pretty much always in EV except when I’m on a road trip, which is pretty rare, and is pretty much entirely in HV. So, the circumstances of when I’m in each mode are pretty easy to separate by time frame. Maybe that’s just me, though...

    By the way, I think it’s called “MPGe” rather than “eMPG,” and in my view at least, isn’t a particularly useful unit of measurement. Also, I don’t think anything on the P.Prime computer calculates/reports it. It does report miles/KWh, which I think is much more meaningful and usable.
     
  5. goinskiing

    goinskiing Active Member

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    Turns out there's several screens in the MID in the ECO diaries that show the kWh\Mile for the day. I think for just HV operation I will just use trip A when\if it ever kicks in.
     
  6. mr88cet

    mr88cet Senior Member

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    Yes, I use those. I don’t think there are any screens that calculate or report MPGe, though.
     
  7. GrandRapidsPrime

    GrandRapidsPrime New Member

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    I do believe not showing MPG and MPGe separately is quite the oversight by the Toyota engineers. I have just had my Prius Prime for a little while and the MPG number becomes meaningless to me and it is hard to see how to get the most out of the ICE without starting new trips. All these screen full of numbers and that can't be tracked? Makes me wonder if there is an after market scanner you can put in the OBD2 port that would do this?
     
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  8. bruceha_2000

    bruceha_2000 Senior Member

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    Just got my Prime Advanced Tuesday after my '09 was totalled Saturday, it replaced my '04 which was totalled in 2012. I wish people would stop running into me!

    I'm totally confused as to what MPG I am getting, hybrid, EV or combined?? I bought the car 60 miles from home, test drive then drove it home on the interstate at IIRC 60 MPH avg (no real traffic), last 6 miles at or below 40 MPH. The traction battery started with no charge (car was in the showroom). The MPG shown was about 25 MPG which is ridiculous and unbelievable especially since the fuel gauge had barely moved. Every Prius we have owned (4 Gen IIs, 2 remaining both '06, and a Gen III) never got below 40 MPG for a full tank in the winter with snow tires, 45+ more normal; over 50 MPG, closer to 55 is normal, in non winter months. On clear roads and non winter tires I would expect that trip to be over 50 MPG in the Gen IIs, and a bit higher in the Gen III.

    The ODO currently reads 175 miles at 36 MPG. That includes:
    • the test drive and 60 mile drive home
    • a 13 mile round trip in EV Auto (battery pre-charged)
    • 55 miles with 6 miles EV, 15 interstate miles EV Auto, then switched to HV, some low speed EV then return 15 interstate miles in HV, the last 6 in EV, battery to 0% as I pulled in at home (battery pre-charged)
    • today's 15 mile EV trip (battery pre-charged)
    The fuel bar is down 1 mark from full.

    I'm drinking from a firehose here trying to understand this new car. Is there any way to know what the gas MPG is (for fueling calculations), or the overall MPGe or ???? And is there a screen that shows current actual MPG?
     
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  9. Salamander_King

    Salamander_King Senior Member

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    Don't worry.about the dismal mpg showing this early. 175 miles is nothing. It probably includes a lot of engine idling with AC on high at the dealer. Your mpg will only be going upward from hear. Reset one of the tripMeter to reset the average mpg on it and report back after driving a few weeks with EV only. TripA should show 999 mpg if all EV and ODO should have much improved mpg now. If you do drive longer distance daily then report after a first gas fill-up, again reset TripA should show far better mpg than ODO.

    There is a way to display split screen on MID that will show current instant mpg while you are driving, but it would be meaningless if you are driving mainly EV. Well, average mpg displayed under ODO and Trip are also meaningless if you do charge and drive EV.
     
    #9 Salamander_King, Mar 2, 2019
    Last edited: Mar 2, 2019
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  10. axle2152

    axle2152 Active Member

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    The best that the Prime does on calculating EV economy is the bar graph showing miles / kWh and the Trip meter showing average mi/kWh, which doesn't really answer the question. In practice the Prime for me averages about 4.5 miles / kWh, a good bit less when it is cold and sometimes over 5 mi/kWh in the summer. Plus the ICE will run more efficiently when it's warm so depending on how far you drive and how much EV driving you do, some people have gone over 3,000 miles on a tank of gas...

    That being said the dealer I got mine from (Hoffman Toyota in Simsbury, CT) put in a full tank and charged it up overnight. So kudos to them. They should have provided a tank of gas and probably should have charged it for you while you were finishing up paperwork and such. Pretty sure a tank of gas is something factored into the price of the car...they usually will either fill it up or give you a gas card.

    That being said, you can bet that iding and test driving is why your average mpg is very low. I'd just go top off the tank, reset the trip meter and go from there. I didn't experience any sort of break in mileage, the car in my case got great fuel economy right from the start. I drove mine from Connecticut back to North Carolina and was able to average about 56 MPG on the highway (no EV driving).
     
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  11. bruceha_2000

    bruceha_2000 Senior Member

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    There was a full tank of gas when I started home, it was < 1/4 during the test drive.

    For the driving I usually do, I could go 10 weeks on 10 gallons of gas if the ICE MPG is 55. I guess that is the number I'm trying to figure out. Or maybe there is no ICE MPG calculation?? It is kinda nice to know your expected long term MPG on a steady state (ie interstate at a given speed) longer trip that well exceeds the EV range. In the past I've used GasBuddy to find cheap stations about the time I will have run through about 10 gallons. This is a preplanning thing since I don't have a smartphone.

    I'll be driving 225 miles one way to MA a week from Tuesday. I know what kind of MPG I would get in my Gen II having made that trip in all conditions about 200 times in the past. The PP is supposed to get noticeably better MPG than the Gen II and I guess my OCD brain wants to understand how much better.
     
  12. Salamander_King

    Salamander_King Senior Member

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    Unfortunately, the mpg displayed are not exclusive of HV. Any EV drive you do will increase the mpg artificially. In theory, if you drive only EV (less than 25 miles) your mpg is infinity, but the Prime display max out at 999 mpg (199 mpg for my 2017 model). The best way to get HV only mpg is not to charge and drive HV only. When you are driving 225 miles one way, if you fill up the tank right before leaving, and make sure you have not charged the battery or use HV only for all the drive, on your way home when you fill up the tank, you should have HV only mpg on mostly highway drive. In summer my Prime gets around 50 mpg at 65-75 mph on a highway, but in winter I would guess much less especially now with snow tires on.
     
    #12 Salamander_King, Mar 3, 2019
    Last edited: Mar 3, 2019
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  13. bruceha_2000

    bruceha_2000 Senior Member

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    Only 50 in the summer? I guess it depends on where and how you drive. A full summer tank at 50 is at the low end for our Gen IIs. However my sister has an '05, lives in massively overpopulated So. Cal and for her a 45 MPG tank is good.

    More than likely I'll drive to MA and fill up there since gas is around $2.20 there and it is $2.49 here. Won't likely have any EV range left before the return trip so that will be a good "ICE MPG" test.
     
  14. Salamander_King

    Salamander_King Senior Member

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    Prime has basically the same fuel efficiency as regular Prius, 55 city/ 53 combined /54 highway. As you know, it does better on city drive. I can get above 60 mpg (calculated) for my normal summer commuting drive with average 30mph. On highway speed of average 70mph, I was getting 53.2 mpg calculated (56.8 mpg displayed) when I did on a single tank without any EV drive one time with a full load. I am sure you can get better if you drive slow and no AC and no passengers.
     
    #14 Salamander_King, Mar 3, 2019
    Last edited: Mar 3, 2019
  15. bruceha_2000

    bruceha_2000 Senior Member

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    53 MPG at 70 MPH is pretty good. There are no 70 MPH roads in VT though there are some in northern Maine. I guess that "no 70 MPH roads" part needs to be qualified. There are no roads posted at 70 though there are plenty of people who think 65 means 75. If I'm in a hurry, I'll drive speed limit. If not in a hurry and the road isn't busy, I found that summer driving 55 MPH = 55 MPG in my Gen IIs.
     
  16. Salamander_King

    Salamander_King Senior Member

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    In Northern Maine posted speed limit is 75mph, but if you drive at that speed, you are likely to be tailgated by a logging truck driver. IIRC, 55mph is the posted minimum speed, which means if you drive slower than that, you could get a SPEEDING TICKET. LOL
     
    #16 Salamander_King, Mar 4, 2019
    Last edited: Mar 4, 2019
  17. bruceha_2000

    bruceha_2000 Senior Member

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    Same is true in Vermont ... except the minimum is 40, below that you have to turn your emergency flashers on.

    Found the extra 'features' on the trip button today. MPG since last start looks useful. I'll have to see how accurate the distance to empty is since that is basically what I used my known MPG under various conditions for in the Gen II.
     
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