49mpg for the Plug-in Prius seems low!

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by RaelGabriel, Sep 23, 2011.

  1. windstrings

    windstrings Certified Prius Breeder

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    Seems the pie is half baked but cost a whole lot more, with little payoff for the hassle of plugging in.
    Once again, I am dissapointed because I keep expecting more from Toyota.
    I have zero incentive to buy a car for more money with worse gas mileage ......surely I'm missing something!
     
  2. chenyj

    chenyj Member

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    PiP has only 15 mile EV range per charge. In long distance highway condition, it is very similar to regular Prius. It is actually less efficient to charge the battery with gas and use the energy for later EV drive. There is significant loss when energy is transferred from one form to the other. And also the equivalent electricity cost from grid is only 1/3 of the cost of gasoline.
     
  3. cwerdna

    cwerdna Senior Member

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    Depends on where. There's huge variance in cost of electricity depending on the region. Take a look at the findings at 2011 Chevrolet Volt and Nissan Leaf: May Fuel Economy Update and Energy/Environment - Automotive Engineering International Online

    We had some discussion and examples of electricity prices at http://priuschat.com/forums/prius-h...le-range-87-mpge-32-000-a-18.html#post1390311. The DOE table of costs by state seems to have moved somewhere unknown so you'll have to look at the archived version at Electric Power Monthly - Average Retail Price of Electricity to Ultimate Customers by End-Use Sector, by State.
     
  4. fuzzy1

    fuzzy1 Senior Member

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    The ability to do a bunch of your commute miles with no gas at all?

    Plug-in hybrids are not meant to get better gas mileage than gas-only hybrids, or even regular gas cars. Their reason for being is the other, all-electric miles they can rack up without touching the gas tank at all. This PHEV Prius is not counting those in its gas-only 49 mpg rating.
     
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  5. radiocycle

    radiocycle Active Member

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    Hi windstrings, long time no see...

    We live in the small town of Morro Bay. We travel once a month to the SF Bay Area which is 250 miles to the north. We are both retired so there is no daily commute. During the week we run errands around town of 2 or 3 miles and on Mondays go to the farmers market in Los Osos, about 5 miles from home.
    So with a schedule like ours, you can see how the Prius Plug-in is the perfect car for our needs!
     
  6. Roadburner440

    Roadburner440 Member

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    The main reason you can not recharge these Li-Ion packs with engine power is it would require a substantial generator to do so. So on top of powering the AC, car, and other accessories it would also need to be able to recharge the battery at a minimum of 120V@12 amps or so... Either way using the engine generator at that amount of power you would need to drive for 3 hours to recharge the battery. So it really does not make sense to do so. I think if the Volt or PiP could recharge the battery from the engine gen it would actually make very little difference overall as any range you gain would be quickly used up cause the engine to continiously kick on/off. On the Volt I have noticed very little gain from even doing regen braking.. It says on the energy flow meter that I have power going back into the back, but range on the screen does not change. I think the PiP is a good concept, and it certaintly gets better mileage than the Volt once the juice is gone. Plus the drag a generator would run trying to recharge the on board batteries would probably drag the gas mileage down rather significantly.
     
  7. giora

    giora Senior Member

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    Source?

    Toyota did state a battery improvment of 15% over the prototype.
    The prototype was quoted as 23.5 km EV range in the Eropean test cycle, 15% improvement is 27 km @ the same test.
     
  8. gwmort

    gwmort Active Member

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    I can tell you on my Volt the number for the range rarely goes up, even when the true range does. If you have a lot of regen, like a long downhill run you'll see the juice flow into the pack but the number won't rise, but by the same token, you may go 2-3 miles before it drops a number either.

    In the same situation if you regen a lot then immediately shut the car off and back on again it prompts a reassessment by the algorithm and the display will show the extra numbers.
     
  9. Jeff N

    Jeff N The answer is 0042

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    See page 26 in the document below where they state an electric range of 23km based on the European test cycle.

    http://media.toyota.eu/Lists/EMS Documents/Frankfurt Motor Show/Frankfurt 2011/Frankfurt_2011_EN.pdf

    My impression is that Toyota did not state a battery improvement of 15% but that some media reports assumed that was true or some other media reports described a 15% increase in electric range from 13 to 15 miles. What 15% battery improvement do you think they made and what is your source?

    If Toyota has stated in the past that the prototype Plug-in had an electric range of 23.5 km on the European cycle then the production Plug-in range would be unchanged.

    I'm not that familiar with the history of Toyota statements about the range (and based on which test cycle) of the earlier prototype plug-in. I know that various people like john1701a have been able to borrow the prototype cars for extended test driving and have reported their own experiences. I don't know if Toyota themselves have made previous statements about the prototype electric range or the usable SOC of the 5.2 kWh prototype battery.

    The nominal battery capacity of the production Prius Plug-in actually shrank about 15% from 5.2 kWh to 4.4 kWh. However, that's not really relevant. What matters is what the actual available kWh are and that is based on the usable SOC range. As far as I can tell nobody really knows what that is yet for the production car.
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    49mpg is the mileage in hybrid mode. If you combine the two, it's 87mpge (equivalent mpg).

    In the production model, there is the option to switch between HV and EV mode so in your case, you would just drive the car in HV mode on the expressway then switch to EV for the last 10 miles. That might be better than trying to initially run in EV mode for the first 15 miles.

    Also, your current Prius may charge up to 7 bars on the highway but it'll never go to 8 bars unless you go down a hill. The same logic can be applied to the PHV. You won't get the full 15 miles back unless you go down a hill.
     
  11. SageBrush

    SageBrush Senior Member

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    I think Sergio posted a video of a Toyota spokesperson saying range had increased 15% from the prototype, but I agree that we will have to wait for the EPA label to be sure of range -- or Toyota can publish usable battery capacity, which is what I am interested in.
     
  12. lensovet

    lensovet former BP Brigade 207

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    what's even less efficient is using the gas engine to keep yourself coasting above 65 mph and not using excess power that's not used to move the car to charge the battery. that's all the OP was saying. if you're driving on flat or slightly downhill highway terrain, your ICE will still be up and running, and the current Prius will use excess power to drive the generator to charge the battery. presumably the same scenario should be possible in the PHV, and to a greater extent because of the larger battery.

    i'm not sure why this is so controversial.
     
  13. giora

    giora Senior Member

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    Your source is outdated and relates to the prototype PHV and not to the newly announced version. (somehow I feel you knew it when posting).
    I have no reason to doubt the 15 miles range announced for the US version (and they know how to simulate EPA test). European version may differ.
    Good luck with your new Volt.
     
  14. Jeff N

    Jeff N The answer is 0042

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    This document appears to be a brochure given to members of the media to help them cover Toyota's new vehicle announcements at the 2011 Frankfurt Auto Show just a week or two ago where they just announced the production Prius Plug-in. It is probably the most up-to-date and detailed Toyota document on the production 2012 Prius Plug-in that is available. Everything else we have seen already consists of either press articles written with this document as a background briefing source document or Toyota press releases, retail-oriented web site pages or introduction speeches that have less detail. I found it originally while doing a Google search.

    It notes where there are differences that are region-specific (only European versions get the EV-City button, for example). See page 32, for example, where it discusses the new 4.4 kWh battery pack size.
     
  15. adric22

    adric22 Ev and Hybrid Enthusiast

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    I have to admit. I really expected the PHV to get even better fuel economy when running on gasoline. I Figured the larger battery and inverter would give more electric boost when accelerating than the standard Prius, allowing the gas engine to work less. I had always assumed the reason Toyota limited the capacity of the battery and inverter in the cordless version was simply a cost/benefit ratio and decided on the best compromise.
     
  16. giora

    giora Senior Member

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    The larger battery gives a big energy (kWh) boost, translated to EV range, on the expense of power (kW) boost. Apparently, it is give and take situation.
     
  17. fuzzy1

    fuzzy1 Senior Member

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    I don't follow your reasoning. Running on gasoline, all the energy, even the portion that goes to the electric motor, must ultimately come from the gas engine. Unless that Atkinson-cycle engine loses a lot of efficiency at the peak accelerations needed in the EPA cycle -- it doesn't -- then there is no MPG gain to offloading that peak boost to the electric side, only to have to refill the battery later when the propulsion load on the engine is lighter.

    The real gain of a PHV is the miles run from the wall plug instead of from the gas tank.
     
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  18. Pinto Girl

    Pinto Girl New Member

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    This'll turn out to be like lots of those GM cars with "Flex Fuel" badges.

    If the price were to become equal to the regular Prius, most folks would buy whichever they could get a better deal on/whichever has the color and options they want and is available, and never think about it much after that.

    If the real gain is miles run from the wall plug, and the car is less efficient in other situations, it seems like a bit of a yawn as far as the general public is concerned.
     
  19. usbseawolf2000

    usbseawolf2000 HSD PhD

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    I disagree. 1 MPG less is no big deal for 15 EV miles you get. That's under aggressive EPA test procedure without blending with electricity. The blended rating is expected to be 87 MPGe. I remember seeing the prototype spec having higher MPG (than Regular Prius) under Japanese test procedure.

    So, carefully driven PiP hybrid mode MPG could be higher than the Regular Prius. Drive it aggressive and it can get 1 MPG lower. It makes sense as it is 123 lbs heavier.

    PiP's battery size is carefully chosen after extensive testing with 2 generations of plugin prototypes. It was not based on a quick napkin calculation like the Volt.

    Research after research show that smaller battery size provide the most benefit to the buyer and environment.
     
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  20. gwmort

    gwmort Active Member

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    Don't underestimate the benefit of those first 15 miles. Electricity is way cheaper than gas and more efficient (at least from the wall to wheels, for get the power plant transmission stuff for now).

    Everyday you drive you start in that super cheap super efficient zone, when you leave it after 15 miles you still are doing almost identical to a conventional prius.

    The plug in will be a noticeable and significant improvement over a conventional prius unless you live in an apartment or something and have no way to charge.
     
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