Ugh...

Discussion in 'Gen 3 Prius Fuel Economy' started by Mendel Leisk, Nov 28, 2019.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    When I first started with Fuelly it was up around maybe 5.2 liters/100 km's (45 mpg). Over the years I've knocked it down, to 4.9 (48 mpg).

    This last spring I retired our old 215/45R17 Michelin Pilot HX HXM4, for Primacy MXM4 (same size), started getting some abysmal numbers. Slowly but very reluctantly improved over the summer, and seemed to eagerly tank in the fall. Just switched over to the Michelin X-Ice2 195/65R15 a while back, and surprise surprise, last tank was a bit better.

    Anyway, entered another tank on Fuelly last night, and happened to notice just now. :cry:

    upload_2019-11-28_9-21-15.png

    Think I need grief counseling... :ROFLMAO:
     
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  2. Grit

    Grit Senior Member

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    Could be the winter blend with ethanol yielding lower mpgs. When I need grief counseling, red wine fixes everything.
     
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  3. Maarten28

    Maarten28 Active Member

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    I think tyres can be a big factor in mpg. I changed mine a year ago and instantly got some 5% less mpg.
     
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  4. dig4dirt

    dig4dirt MoonGlow

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    Tires, mmhmm and how long did you go without the engine block heater?? :whistle:
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah same story here, maybe worse.

    upload_2019-11-29_7-26-29.png

    Oh that's right. Block heater fritzed Sept 23, new one installed Oct 27.

    upload_2019-11-29_7-24-37.png
     
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  6. Grit

    Grit Senior Member

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    Got new tires few weeks ago, my commute has gone from 63 mpg to 59 mpg with 100 mi commute round trip. 10/32" tread is killing me, with 820 treadwear it will take forever to break in. I don't even drive fast enough to take corner turns like a champ either. Miss the 3/32" treads, getting these treads shaved to 5/32" ha.
     
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  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Near-bald tires are smaller diameter too, slightly more rev's per miles. Kind of cheating, but I'll take it. :whistle:
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I miss my Michelin Pilot hx MXM4. They were getting pretty knackered, but the rolling resistance was right up there. :)

    215/45/17 my Michelin premier review | PriusChat

    @bisco recommended Premier A/S, should have listened... :cry:

    Ah, I think the Primacy's will perk up in time. (y)
     
  9. andreimontreal

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    Where do you live Grit? Is this winter mpg? The best I've seen on my car is a very rare 50mpg at most. Either mine is messed up well or I don't know what.
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    I'm guessing @Grit is Boise, Idaho?? He's a bit of a fanatic, stripped some of the interior out IIRC, to reduce weight. I woudln't sweat it, Montreal in winter, 50 mpg is pretty dang good.

    Just doing the math, on ours the lifetime average (5.0 liter/100 km) converts to 47 mpg US.
     
  11. andreimontreal

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    That's rare, very rare and at mild tempsl 50 mpg is 4.7l/100km. I usually see 5.5l/100km on highway if I drive 20+km; otherwise it can be up to 6-6.5L. For short distances I saw anything from 7-9L at mild temps, to 9,10, even 20-30l at hars temps like -15C. But with all the issues I've been getting, who knows what's justifiable anymore.
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    I get clinically depressed when displayed hits 6 (liters per 100 km). :( To rub salt in the wound: displayed is optimistic, typically around 7~8 percent in my experience. :cry:

    Could be the ongoing saga of dragging brakes is a factor with you? I think you'd zeroed in on the parking brake not releasing on one side??
     
  13. andreimontreal

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    So it's normal for winter?
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Here's ours, all of 2018, and to date in 2019. A couple of things seemed to have impacted this year: new tires (and they're the 17", which always knocks you down a bit), and block heater failure (we use it semi-religiously). You can see we're not doing a lot of driving, and a fair bit is shortish trips, though we try to avoid impulse drives, consolidate errands. Anyway, fwiw:

    upload_2019-12-20_17-37-50.png
    And yeah, apart from 4~5 months each winter, we're on 215/45R17. Unlike @Grit, we've got all the upholstery in place, a 20 pound jump pack and another 20 pounds or so of just-in-case stuff in the hatch tray, lol.
     
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  15. andreimontreal

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    That is awesome. Did you have to input all that data by hand? Or fuelly somehow gathers it automatically; just curious as I've never done it. Not that it scares me; I collect way more data from my car for work.

    Thanks for sharing; just as I suspected many times before, there's something wrong with the car and it's deeper than dragging brake pads.
     
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  16. Mendel Leisk

    Mendel Leisk Senior Member

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    I do my spreadsheet entry first, just copy the previous line down, then edit fields as needed. Final step is to go to Fuelly, where I basically enter "date", "odometer" and "liters". I put a link in the spreadsheet, you can see it top/right corner.

    See the steady discrepancy between dash and actual? Toyota likes to BS...
     
  17. andreimontreal

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    I was curious to see if there was some sort of automated system; I keep tabs for taxes. Not that there's much info, just for automation.

    Yeah I've heard that piece of info in excess by now. So many people pissed off because of the hidden facts of the official Prius mpgs.

    I was wondering if I would ever switch for another car but I come back to the same reasons. For me the large size and the electronic side of it is actually a plus - borderline perfect - since I wanted to do a travel mod out of this car. I haven't seen another hatchback that can quite compare. I'll post stuff about it when it's ready so you'll see what I mean eventually.
     
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  18. Raytheeagle

    Raytheeagle Senior Member

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    He’s a Northern California resident who is in the Bay Area frequently:).

    Close enough to attend our meetups;).

    His interior is stripped out, but since it is only him, why not(y).
     
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  19. RMB

    RMB Senior Member

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    Got new tires in July, since then I haven’t gotten over 50 mpg (calculated) a tank:cry:. The new route I need to take sure doesn’t help neither.
     
  20. Attila Fekete

    Attila Fekete Member

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    The consumption really depends on your driving style and usage. In Spritmonitor the average is between 3,14 and 7,5.
    The highway is ~6 l/100 km for me too, but that means tgat I try to keep the 130km/h - which is ~120km/h by GPS (~74 mph).