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Manually Charging my 2010 Prius to avoid running the engine on startup?

Discussion in 'Gen 3 Prius Technical Discussion' started by Unresolved_ERR, Oct 6, 2020.

  1. Unresolved_ERR

    Unresolved_ERR Junior Member

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    Hello all,
    I am very new here and as a Prius owner. I have read some of the top threads and done some of my own research into getting better mileage. I have tried for a few hours now to find a thread with this question, but to no avail.

    I am aware (as a result of a stickied thread) of how and why the engine starts up nearly as soon as the Prius starts. I do not fully understand these "warm up" phases as I am not much of a car person -- but I also know it really knocks my mpg down, at least during the start of the trip, so I was wondering a few things.
    1), would it be better for the gas mileage if I avoided this "engine startup" (stage 1,the warm up thread calls it)n some method - not running the gas engine until I needed it in a 45? Would it be worse for the life of the engine itself?
    2), if it is both better for the gas mileage and (at least) not much worse for the life of the engine itself, what would be the best way to circumvent it? Would manually charging my non-plug-in (regular hybrid) prius be a good idea, especially as someone who is not remotely experienced with electricity?

    I figure they would not have designed it as such if it was not best for one (engine life) or the other (mpg), but I am just curious.

    My most efficient drive coming home from work is 70.9 MPG (I work a night job so the traffic conditions coming home at 3:30 or 4 AM are favorable), and I think that's the upper limit of what the 2010 Prius is capable of, but this is one of the last obstacles I have not been able to push through with my own research and statistics in the few months I have had the car.

    Thank you in advance for taking the time to read and answer.
     
  2. PriusCamper

    PriusCamper Senior Member

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    If you owned a plugin electric Prius you could have the option of driving around for a while before the engine started but it doesn't work that way with a regular Prius. The engine and electric motor work together for maximum MPG efficiency... If you use too much engine, or too much electric and not a balance of the the two your MPG gets worse.
     
  3. Vman455

    Vman455 Senior Member

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    Unfortunately, charging the pack would not stop the engine from starting when the car is turned on; it does that to warm up, as you noticed in the thread you mentioned. The engine will, as far as I know, turn on at startup no matter the state of charge of the battery. However, you could possibly prevent it starting by heating the coolant using a block heater, although I'm not sure how warm those get.
     
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  4. Unresolved_ERR

    Unresolved_ERR Junior Member

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    When I first purchased the car, I would brake somewhat hard coming off the highway. this has twice now charged the battery to 8 bars, and on a few occasions I would get to school and park with 7. When I got back to my car after class an hour or two later, sometimes it wouldn't run the engine, I believe it may have something to do with the outside temperature, like if it is warm? Although there were other times where it would start up regardless, and I do believe that is due to the engine warming.

    Thank you for your response.

    Yes this is true. I wish I had known that plug-ins existed...I would have tried to get a 2012 plug-in if I had known. It was only weeks later when I discovered they exist, and apparently no one else in my entire family or at my work place had ever heard of them. Perhaps once I have graduated...

    Thank you for your response.
     
    #4 Unresolved_ERR, Oct 8, 2020
    Last edited by a moderator: Oct 8, 2020
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    When I use our block heater for a couple of hours, in mild-or-better weather, ours will sometimes go into EV. Till I round the corner out of our cul-de-sac, and speed climbs above maybe 15 kmh.

    In short: there's no advantage, no upside to forcing the car into EV.
     
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  6. Unresolved_ERR

    Unresolved_ERR Junior Member

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    Ah, makes sense. I saw somewhere else that you can use the EV button when the car first starts to force the car to avoid running the gas engine at first - but it will do just that, limit your speed to 15 kmh / 9 mph before it cuts EV mode and starts the engine either way.

    Thank you for your response.
     
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  7. royrose

    royrose Senior Member

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    Another reason for the initial engine warm up is to keep emissions low. The gas engine burns fuel most efficiently (both for mpg and emissions) once the engine reaches optimal operating temperature. You just have to live with the warm up.
     
    #7 royrose, Oct 8, 2020
    Last edited: Oct 8, 2020
  8. Grit

    Grit Senior Member

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    o_Oo_Oo_Oo_Oo_Oo_Oo_Oo_Oo_Oo_O
     
  9. fuzzy1

    fuzzy1 Senior Member

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    No, unless you can achieve the entire trip without starting the gasoline engine. E.g. with an electric car, or plug-in hybrid with sufficient electric-only range, or an extremely short trip that is within your regular Prius's all-electric range, basically a few blocks at under 10 mph.

    If you are going to use this engine at all during a trip, it needs to get warmed up, and this requires a certain amount of fuel. For the overall trip, there is no meaningful fuel savings to delaying warmup until you reach a faster speed zone, it still needs the same amount for this function.

    You can reduce this warmup fuel need by pre-warming the engine with an electric block heater. But the electricity costs money too, and the block heater is unlikely to get the engine warm enough to boost the threshold EV-only speed above 9 mph to a more useful 25-ish mph.
     
    #9 fuzzy1, Oct 8, 2020
    Last edited: Oct 9, 2020
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    My EV use is good for a "stealth departure". Just sayin'... :whistle:
     
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  11. Tideland Prius

    Tideland Prius Moderator of the North
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    An engine block heater will reduce the warm up time, thus reducing the mpg hit. Blocking the lower grille (50% below 50°F and 100% below freezing) can help reduce cooling when the engine is off ans you’re driving in EV mode.
     
  12. bisco

    bisco cookie crumbler

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    can you force charge a gen3 like gen2?
     
  13. Maarten28

    Maarten28 Active Member

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    What does help when you charge the battery is that the first few minutes during the warmup you are driving electric. No power flow from the ICE to the wheels (when you don't really step on it). So for that it would have a positive effect if you could manually charge the battery to 80%.
    But it won't prevent the engine from starting when it is cold.
     
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  14. fotomoto

    fotomoto Senior Member

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    Years of watching this and other hybrid boards have shown me there are distinct phases of hybrid ownership many folks go through:

    First is the amazed/excited/happy phase to see the big FE numbers one has never encountered before.

    Next is the confused/questioning stage from not understanding how it all works.

    Then comes the research/education phase when one learns the tricks.

    This leads to the implementation phase of said techniques.

    The next phase is dependent on the individual: either you hit the big numbers and are content or you become frustrated; either because of the application of said techniques is too difficult (tons of threads on this) or you simply don't hit the big numbers you've seen others post.

    The next phase is where I am now: turn off the consumption screens and just drive the damn car. :)

    Good luck in your journey!
     
  15. bisco

    bisco cookie crumbler

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    i think if you shut it down after it starts, it won't start again until you need it
     
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  16. Unresolved_ERR

    Unresolved_ERR Junior Member

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    Yeah, understandable (y)

    That's what I was thinking!

    I'm not sure how safe it would be for obvious reasons, and I'm not clearly not trying to hurt myself.

    It's something I would have to look into much more.
     
    #16 Unresolved_ERR, Oct 9, 2020
    Last edited by a moderator: Oct 9, 2020
  17. tvpierce

    tvpierce Senior Member

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    The thing to remember about the Prius (and any other non-Plug-in hybrid) is that 100% of the electric power is directly or indirectly derived from running the ICE.
    "But what about the power harnessed from re-gen braking," you say? That's re-claimed kinetic energy that originally was created by the ICE.
    The ICE is the power source. The battery is a storage device. That's it... period. You can force the system to run in EV mode for a limited time under some limited conditions, and you can drive in a manner that minimizes the amount of time the ICE runs, but in doing so, you're not gaining any long term MPG advantage. All you're doing is depleting the battery charge, which will then need to be replenished. How will it be replenished? By running the ICE.
    It's a closed system. There is no "free" energy.
     
    #17 tvpierce, Oct 15, 2020
    Last edited: Oct 15, 2020
  18. fotomoto

    fotomoto Senior Member

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    Once that is realized it makes it much easier to "turn off the gauges and just drive it".

    Then, after a bit...... one begins to understand why adding a larger battery and a plug to the closed system opens things up and make a lot of sense/cents.
     
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  19. Unresolved_ERR

    Unresolved_ERR Junior Member

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    Yes, exactly. When I first got the car, I thought it would be best for MPG to run off the battery as much as possible, since it doesn't take gas, but it didn't take me longer than a week to realize that it would just run the engine to charge the battery, giving significantly less MPG, because as you said, that's the actual power source.

    In any case, I suppose it's best I just drive as efficiently as possible (within reasonable limit, of course) until later when I can afford a plug-in so that the gas doesn't have to be the only power source. As fotomoto said, it makes a lot of cents...

    Thank you for the response!
     
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  20. Grit

    Grit Senior Member

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    The bar graph below shows the last 6 months of MPGs, mine gets driven a lot and ICE runs 95% of the time.

    IMG_3153.JPG
     
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