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Prius Eco 58 MPG vs Prius 54 MPG - What's the difference?

Discussion in 'Gen 4 Prius Fuel Economy' started by cyclopathic, Nov 18, 2015.

  1. KrPtNk

    KrPtNk Active Member

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    I noticed this in a Motor Trend article on 10 interesting facts about the 2016:

    "To ease the load on the climate control system, the 2016 Prius comes with a heat-insulating windshield in the Eco trim to ensure that infrared ray transmission is reduced and the cabin is comfortable in hot weather. A positive temperature coefficient ceramic heater warms the cabin quickly without relying on the engine coolant to get up to temperature."

    I don't remember hearing about a ceramic cabin heater before. Has this been mentioned before?
     
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I know it was a feature of the Gen 2 Prius, I assumed it was a feature of all since.
     
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

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    It is also in the Gen-1, 800 W if I remember correctly. I've got the electrical schematics at the house.

    Bob Wilson
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    It's using electrons, ultimately from the hybrid battery? With our 3rd gen, don't think the heat wakes up till coolant gets to around 50C.
     
  5. roflwaffle

    roflwaffle Member

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    not cool. Double Shotgun!

    ^ Haha! Well done. ^

    Back on topic, the I'm thinking the efficiency improvements are or could be due to...
    • Better LRR tires
    • Better engine efficiency via taller PSD gearing?
    • Better engine efficiency via less engine power required during acceleration?
    • Better aero (underbody, engine bay, ?)
    • Lower cooling (and heating) loads?
    • Tweaks to the HVAC system (maybe a heat pump for heat?)
    • ???
     
    #145 roflwaffle, Jan 26, 2016
    Last edited: Jan 27, 2016
  6. KrPtNk

    KrPtNk Active Member

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    That's interesting. I don't now have a Prius, but have tried to learn about the features of the car. The electric heater makes perfect sense. I am glad they included it in previous models. The way it was presented in the article they made it seem like a feature unique to the Eco.

    Thanks
     
  7. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    It may have gotten larger, in the Gen 2, it was just so defrost would work before the water temp rose. Perhaps they can actually heat the whole cabin now.
     
  8. bisco

    bisco cookie crumbler

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    i have never felt any heat in my 3 pri until the engine warms.
     
  9. AKCoffee

    AKCoffee Junior Member

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    If it's electrically driven and in the gen 3, is it on its own circuit with a fuse I can pull or can we locate the wires so I can snip them? Sounds like energy conversion losses and extra ware and tare on the pack, , I'd rather wait for the coolant to get hot and I'm in Minnesota.
     
  10. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    On my Gen 2 there were fuses, on page 48 of this PDF (page 400 of the manual) you can see 2 PTC heaters. (Positive Temperature Coefficient: the hotter they get the more their resistance rises, preventing over heating and lowering electrical draw)

    http://www.toyota.com/t3Portal/document/om/OM47614U/pdf/sec_04_03.pdf

    I did not see any fuses marked PTC Heater in the 2015 owners manual.
     
  11. David Beale

    David Beale Senior Member

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    GIII has the exhaust heat recovery device, so those barely noticeable 400W heaters (there were two as I recall) in the GII were not needed. I only noticed them once, on a fall day, ambient temp. just above freezing. The air the system was discharging was just barely warm. Never noticed an effect in winter. I suppose -30C air is just too much for them.

    The GIV has an enhanced exhaust heat recovery device, according to the info. posted. I suppose the electric heater reduces engine run time for warmup. That would be a big fuel efficiency gain. Most of my "fuel wasting" or "guzzling" is due to warmup.
     
  12. AKCoffee

    AKCoffee Junior Member

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    Which is it in G3 and G4: exhaust heat recocery (scavenging heat energy otherwise going to waste out of the tailpipe) an efficient good thing, or electric resistive heat to quick warm the cabin/cat/motor or some combination? Given the amount of current it would take to move any of those loads an appreciable amount and the energy to do so ultimately comes from the gas tank, it would take a lot of convincing to get me to believe any electric role is net positive for FE, let alone positive enough to justify stressing the pack.
     
  13. AKCoffee

    AKCoffee Junior Member

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    I'm no engineer maybe my assumptions are flat wrong, but 800 watts sounds like a big additional draw.
     
  14. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    800 watts = ~ 1 HP
     
    mmmodem likes this.
  15. GasperG

    GasperG Senior Member

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    The question is when do those two 400W heaters actually work, my guess is they only work when you select front defrost, with dedicated button and cooling fluid is too cold. If I remember correctly the heaters heat air directly and not the cooling fluid.
     
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  16. CraigCSJ

    CraigCSJ Active Member

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    It seems to me that tire pressure is a large reason for better mileage in the Eco. They probably must test at the recommended pressure written on the car, and I believe the pressures written on the Eco are higher than on the other models.
     
  17. bisco

    bisco cookie crumbler

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    i don't know how big a part it plays, but i think you are correct on the pressure and testing.
     
  18. bisco

    bisco cookie crumbler

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    the problem with this, is that the front defrost button starts the engine on the pip.
     
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  19. eric1234

    eric1234 Active Member

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    On my 2016, I see that the fuse compartment (up front on the passenger's side) - has 2 empty spaces for PTC. I also notice that there are many other empty fuse spaces in that as well as the other fuse compartment.

    I think I once remember reading/hearing somewhere that the 2010 did have these (but honestly, I never looked). I also think I remember reading/hearing that in some instances, the Dealers failed to install these as part of the PDI (pre delivery inspection).

    So, does anyone know if: (1) My 2016 Three *should* have fuses there; or (2) It is an option on higher models or other world markets, that is not part of my US Three??
     
  20. Y-Zer09

    Y-Zer09 Junior Member

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    Also, how is trim 2 NiMH getting the same MPG as the lithium battery versions