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ECO vs PWR mode in 2010 Gen III Prius

Discussion in 'Gen 3 Prius Fuel Economy' started by naudurivsm, Nov 8, 2010.

  1. naudurivsm

    naudurivsm New Member

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    Hello,

    I got the Prius new on 10/23/2010 and for the 1st week around 650 miles I did get to 50.5 mpg consumtion rate. but then it dropped back consistently to today's low of 47.9 mpg with about 1300 miles.

    I was using the PWR mode when I get to a uphill section on the road and when the car was slowing down and immediately switch back to ECO mode after 10-30 seconds on PWR mode (after I pass the uphill section).

    Is this affecting the mpg negatively?

    what are the best practices of using or switching the ECO / PWR modes dynamically while driving ?

    what is EV mode for, will it increase the mpg ?

    any other experiences ?

    Thanks
     
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    In general, if you need to move your Prius a short distance when cold, the EV mode can skip warming up the engine altogether. If you parked in the drive way to unload a sofa, and now wish to put it in the garage after your nap on said sofa, EV mode is great.

    Various folks have specific lifestyles where EV mode makes sense, (Draining the battery before a long downhill that will recharge it, or sneaking home without waking the spouse, for example) but there are no other generally useful times for EV.

    (Some cities mandate EV mode for pollution reasons, London I believe)
     
  3. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Agree with all above (FWIW)
    I too played with the EV mode somewhat, but I find that I cannot extend my MPG by using it. Caveat: I’m not a hypermilier, and I don’t play one on TV. I’m just trying to establish a baseline MPG value for something close to normal driving. I usually pay the 5-10MPG premium for using cruise control and A/C. I do not use the power mode at all, instead I usually keep the vehicle in eco mode. The only thing the power mode does (IMHO) is to transform a VERY sluggish vehicle into a a somewhat sluggish vehicle---and you’ll pay a MPG premium for that small difference!!! I find that I can get from here to there in eco mode by judicious use of throttle, when necessary. I haven’t derived a specific difference between gas consumption in Normal and Eco modes. I only have 1200 miles on the car, and I have to devote some of my energies to my full time job.
    My take: (and it’s JUST my take)
    EV mode is useless, unless you’re out of gas and can see a gas station, or you want to do a dead-stick landing at night, or you want to sneak up on a pedestrian.
    Power mode is almost equally useless, unless you’re a hopeless gear-head that HAS to drive a Prius, and doesn’t care about fuel efficiency---or you’re a dedicated hypermilier and there’s some hidden benefit to using this mode that I haven’t discovered.
    There is a difference in the throttle feel between “normal” and eco modes, and I “presume” that there’s a corresponding fuel efficiency delta, but I haven’t resolved that. Like I said….I leave it in Eco mode and just try to relax and get to my next office. The only reason I’ve put this much energy in determining fuel efficiency is that my boss also has a company-provided Prius, and he’s always twisting my tail about how he gets crazy good MPG figures with this car (supervisors obviously aren’t measured for JOB efficiency!)…and how I don’t. My 1200-mile MPG is under 50---currently about 48.5…but I’m working on it!! :D
    Good Luck!!!
    EDIT: I just caught that..THAT'S FUNNY!!!!.If you parked in the drive way to unload a sofa...
     
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  4. naudurivsm

    naudurivsm New Member

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    I drive 110 miles roundtrip to work. 96% of which is on highways. I have already 1460 miles on the car ( from 10/23/2010). I am in fact trying all modes at different circumstances and trying to get a feel of the vehicle and how to make it more efficient. my observations so far and what I understood from the above replies:
    1. EV mode is all battery power mode right?
    2. ECO is the normal driving with auto switching between GAS and Battery.
    3. PWR mode is also same as ECO with the ability to accelerate quickly where needed. Is the above right?

    so my next question is how far the vehicle can go in EV mode and what speeds I can go ?

    Thanks
     
  5. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    I'm still a noob to this car, but I believe that EV mode will only successfully stay engaged if your speed is under 25, your vehicle is warmed up, and your battery is not low. I've read where some of the hypermilers use it under very limited conditions to keep the ICE from engaging due to excessive throttle input, (like on a hill, or to squirt through an intersection) but from what I'm understanding anything you take out of the battery in EV mode, you have to put most of it back into the battery with the ICE---so your net benefit is pretty close to zero...unless you're like, the duke of regenerative braking.
    How far you can go in EV mode depends obviously on terrain and battery, but I haven't managed to go more than a mile or two, and then it kicks out for low battery---all at less than 25 MPH.

    Good Luck!
     
  6. wick1ert

    wick1ert Senior Member

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    The difference between ECO, Normal, and PWR modes is the throttle mapping. Neither one specificially will deliver better MPG than the other. In ECO, you have better throttle input control with the gas pedal (it's less sensitive) and in PWR it's more sensitive and will provide quicker feedback. There is no additional power in PWR mode vs ECO mode, just a matter of how much you have to push down on the pedal to achieve it.

    EV mode is battery only, but remember that all power to the battery is essentially generated by the ICE and thus is not efficient power. The ICE got the car moving in order for regen to occur, unless you happen to get someone to tow you to the top of a big hill so you can regen down it. Although, an ICE still did the work, it just wasn't the one in your car :). It's limited to 25 MPH with a fully warmed up engine, within specific acceleration amounts. As others said, parking lots, moving the car from driveway to garage/street, etc. is where this is most beneficial. It's not good to use it for any kind of distance.
     
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  7. fotomoto

    fotomoto Senior Member

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    Venkata,

    Your driving route is probably your biggest obstacle. Hwy speeds + hills is tough on any vehicle's fuel economy. Plus I assume cooler weather up there is requiring heater use which forces the ICE to run when it otherwise could be off. You should see better mpg's when the warm weather returns. Also, by then your ICE and tires will be fully broken in.


    Check and adjust your tire pressures too.
     
  8. naudurivsm

    naudurivsm New Member

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    Yes, I have to turn on the heat almost all the time on both sides of the trip. plus specailly in the morning for about 5 minutes before I start for the frost /mist etc to clear.
    The uppish /Hilly strech of road I come across is at 5-6 places and each section is about 100-300 yards so I switch to PWR mode only for those streches as that helps me maintain speed and not cause un-necessary obstruction to others on a highway.
    But I gained back on the overall consumption till today which now stands at 48.6 which is pretty good considering all the facts.

    also I am planning to increase tire pressure by 5 PSI on both fron and rear tires. may be that would help a bit. currently they are at factory/dealer settings
     
  9. fotomoto

    fotomoto Senior Member

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    The power mode doesn't make more horsepower from the motor over eco or normal modes. It is simply a more aggressive software mapping for the accelerator pedal which allows you to press down less on the pedal for the same amount of acceleration than in either eco or normal modes. IOW, it's more sensitive to input.

    Also, are you using cruise control (CC)? That can lower fuel economy (FE) especially in hilly terrain.

    I think 48.6mpg is very good since you are pre-warming the car on cold mornings. Using heat at high speeds should have no effect on mpg since the ICE has to run anyway.
     
  10. Truman

    Truman New Member

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    I have my 2010 Prius for a week and a half with 1500 miles on it. I played with the various buttons, EV, ECO,and Power. They are just toys if you like to play. They set the response of the accelerator, and that is all there is to it. I have forgotten about them and just use normal mode. Mileage is 52.3 MPG. I am very happy with it!
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    I'm thinking that too: that "Normal" mode might be the sweet spot. It's sort of invisible, since it requires a second push of any of the mode buttons to engage, and there's no indicator on the dash for "Normal". Just getting started with ours, on the first tank.
     
  12. timo27

    timo27 Member

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    I agree with pretty much everything that's already been said--the only thing to add, regarding ECO mode, my understanding is it also goes a little less aggressive on the AC when you have the AC on; this might be its only real fuel-economy benefit. FWIW, over the course of 27K mi or so, I've played around a lot with the different modes (except EV, which, whenever I turn it on, responds to my overtures by telling me 'EV NOT AVAILABLE AT THE MOMENT' or something like that, as if it's out grabbing a bite to eat or playing hard to get or something...). My observations--qualitative though they may be--are that you can get pretty much the same mileage in any mode, if you adjust your foot accordingly.

    To be honest, the only reason I sometimes use ECO mode is to make the car seem a little quicker when I don't. ("Seem" is the operative word in that last sentence; the Prius is not a sports car, and that's OK by me).
    ~T
     
  13. SamelCamel

    SamelCamel New Member

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    Don't forget... Mileage will be going down with the colder weather. Most changes right now will reflect lower gas mileage. You will see a gain again once the temperature gets back up in the 80's again.


    -Sam
     
  14. skilbovia

    skilbovia Member

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    Specifically, when the AC is on, ECO mode causes the following behavior:

    If the outside temperature exceeds a preset temperature, the system sill switch to recirculated air mode.

    The effectiveness of the air condidioning will be lower than normal.

    The fan speed level drops below the normal rate.

    The above is directly from the manual. I don't really talk like that:D. Turns out that I ran the AC when it was hot out in ECO mode and thought there was something wrong with it. So if it's warm out and you are in ECO mode don't expect much from the air conditioner.
     
  15. chip_designer

    chip_designer New Member

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    in my experience, EV mode only works if speed is less than 10, as
    long as battery charge is sufficient.
    that works enough for me around my company expansive parking lot.
     
  16. Tideland Prius

    Tideland Prius Moderator of the North
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    Keep in mind that the benefits will be seen in the winter. It's the difference between idling in traffic and reducing the heater load and having the engine shut off.

    I used a combination of ECO and EV mode tonight on the drive home (first "cold" snap and my unusual commute in rush hour traffic since I had a shorter day). EV worked first in the sense that I can force the engine off when I'm stopped in traffic (and travelling below 10mph of course which works best in very slow traffic) and eventually ECO mode shuts off the engine on its own once the engine warmed up. If I wasn't in ECO mode, the engine will idle all the way home since my commute is only 9km (5 and a bit miles) so it never has the chance to fully warm up when it's cold outside.