Prius won’t get over 30mpg after new engine installed

Discussion in 'Prius v Technical Discussion' started by Chardone69, Apr 29, 2021.

  1. ChapmanF

    ChapmanF Senior Member

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    test drive with data logging
     
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  2. Chardone69

    Chardone69 New Member

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    Put a new 12v battery in her today and I’m back up to 33-34mpg. Inverter water pump is ordered from a Toyota dealership I deal with in Richmond Virginia is on the way. Hopefully that cures the lacking mpg.
     
  3. Chardone69

    Chardone69 New Member

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    12v battery posts made me start thinking because last Tuesday my old lady turned on the lightbar when the car was off and in two hours I had to start the car with a jump pack. That lightbar is all leds and should not have killed the battery in two hours.
     
  4. Chardone69

    Chardone69 New Member

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    I forgot to mention that putting a new 12v battery in increased the mpg’s to 34.
     
  5. bisco

    bisco cookie crumbler

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    how many watts does it consume?
     
  6. dmax11

    dmax11 New Member

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    heavy drain on the 12v system could hurt MPG as it would drain the HV battery faster, that being said after a month or so of owning my new to me 2014 V i have changed a few things about how I drive it and regularly get 39.5 mpg on average, mainly I don't use eco/pwr/ev mode at all just leave it in regular mode and try to stick to 70 mph on highways, before when i drove it like i drove my old 08 Prius (like a bat out of hell and 75 mph on highways) I was often sitting down around 37-37.5 mpg these are pretty big cars for the size engine/system they put in them but i sure do love the extra space!
     
  7. Tim Jones

    Tim Jones Active Member

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    I'm getting 44 mpg in mine with well over 250,000 miles.... But I do have a less than a 2 year old Traction battery and 42 in the front and 38 in the back tires.

    Plus my v in Toyota for new master and pump but they have no idea when the pump will be in.
     
    #27 Tim Jones, May 3, 2021
    Last edited: May 3, 2021
  8. TMR-JWAP

    TMR-JWAP Senior Member

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    I don't want to throw a monkey wrench into anyone's gearbox, but a 12v battery is not going to affect how well a Prius can go uphill or not.
    If the inverter were getting hot, it would let you know, as it would display a big red triangle. Struggling to go uphill is an indicator of a power problem or an extremely weak HV battery. An HV battery that is so weak that it can't assist, but doesn't throw a code, is usually due to something dragging the engine down in power, preventing it from keeping the HV battery charged.

    If anyone owns a Gen 2 and is getting less than 43-44 mpg, there is something not right, or there are an extraordinary amount of <5 minutes trips being performed. The Gen 3 should be able to do even better.
     
    #28 TMR-JWAP, May 3, 2021
    Last edited: May 3, 2021
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  9. Tim Jones

    Tim Jones Active Member

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    Have win 10 and works fine.
     
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  10. dmax11

    dmax11 New Member

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    I mean not sure where the 2nd gen discussion came from but my 08 I had for 4+ years never had issues going up hills (so long as the HV battery wasn't already low) and it never saw 40+ mpg with highway driving it was always around 37-38 mpg for me always, only time i ever saw 40+ was if I was in a flat land traffic commute, high continual speeds highway driving with hills involved it never ever reached 40 mpg

    the Prius V which is what is being discussed here does not get 40 mpg highway it gets 39 or so according to toyota and i'll attest that is what i see with mine if no hills involved best trip i had with minimal hills so far i got 41.5 mpg they can get higher if you sit in traffic a lot with no hills just like any hybrid...
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    I'm sorry, are you the OP under a different user name? The Gen 2 was mentioned because that is my "area of expertise" and I guess I made an incorrect assumption that ALL the Gen 3 models were an improvement over the Gen 2 in regard to mpg. Didn't realize the V was that poor. My bad......

    And....as for this....

    the Prius V which is what is being discussed here does not get 40 mpg highway it gets 39 or so according to toyota

    Looks like Toyo says 44/40 for the V, so I guess this "does not get 40 mpg highway it gets 39 or so", which makes no sense, actually is pretty dead on....

    2014 Toyota Prius V Review, Ratings, Specs, Prices, and Photos - The Car Connection
     
  12. dmax11

    dmax11 New Member

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    no of course I'm not, just curious why 2nd gen mileage is even relevant and given that i previously owned and daily drove a 2nd gen for quite a few years threw in my two cents on their actual real world mileage in my experience
     
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  13. TMR-JWAP

    TMR-JWAP Senior Member

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    sigh............
     
  14. Chardone69

    Chardone69 New Member

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    The car has 186k on it and I imagine that hv battery is original. I’ve read that these batteries are only good to 150-180k. So are you saying it’s my hv battery or are you saying it’s something else? Because the battery charges and discharges the way it’s supposed to from what I can tell.
     
  15. ChapmanF

    ChapmanF Senior Member

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    I don't know what the problem is, but it's cool having a car that has traveled a light-second.
     
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  16. Chardone69

    Chardone69 New Member

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    Around town the car gets 33-34 mpg. Get her out on the expressway doing 71-73 mph and it drops to 29.9-30. I just went up a steep grade at 35mph and turned the display over to the energy monitor and the whole time the battery was being charged. I’ve noticed all night that the hybrid battery spends more time getting charged then anything else. My battery health bar on the dash is 1-2 bars below full at all times. The only time that battery is used is under 40mph and to be honest,when in EV mode,the car feels like it’s pulling a semi it’s such a slouch. Bad Hybrid battery ??
     
  17. Tim Jones

    Tim Jones Active Member

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    I've had a bad battery but did not experience the problems your having.
     
  18. Samuel Williams Jr

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    Until you start to data log, you really won't know what is going on? The low mpg average could be caused by a short daily commute? Our 2 Gen gets 40.1 day to day when we stay in Dayton, which is most of the week, short trips less than 6 miles.

    But when I take it further to Carson City 16 miles away once a week. If I reset the mileage from there to back home it shows at least 51 mpg. And it has to climb from 4300 ft to 5000 ft and then back down to 4300 ft to get home.

    And the climb to 5000 is steep! Speed limit is 55 mph but 60 to 65 or 70 ish is still OK ... maybe? But if you wanna be a real tool? Our Prius will climb that hill at 80 plus and not break a sweat? I'm guessing 80 but it may break 90 mph? I don't know? But I do know if you try at the bottom of the hill the SOC will go to Two Purple Bars. And the car will not slow down, it will still continue to accelerate and just recharge later.

    It does it all the all the time and the climb to 5000 ft is the little way out of town. Going to Reno via 341 is at least a 6000 ft climb? And again same deal with the battery it goes to 2 bar's purple at the start and the car does not slow down.

    The speed limit is 45 (I think?) and 60 mph will land you in court! I consider that speed as slow myself because there was Snow on the ground. When I did get stopped (different car), but whatever. But I just made that trip the other day in our "Prius," at the speed limit and to the summit the SOC was two purple bars. And the car did not slow dt own, it was my first trip in our "Prius," over 341 and it seemed that if I really wanted to go back, to the Va. City traffic for a another Speeding Ticket? Our Gen 2 would be happy to accommodate. I thought driving a "Prius," was a get of jail free, card?? But apparently not? :)

    Something is off with your's? And might be the HV Battery ?? But I don't know?? The SOC for the HV battery could be good enough for day to day?

    At any rate your HV battery maybe "Good Enough," for Day to Day? But under stress it falls flat? I don't know?? You have to use a "tool," to see what is going on with it?
     
  19. Chardone69

    Chardone69 New Member

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    I ordered a new traction battery yesterday and the company is coming to install it at my house next Wednesday. $1800 includes installation and a two year unlimited mile warranty on the battery and the labor. I’ll have 200k on that within 18 months. So I’ll probably be getting another one before the warranty is up for free.
     
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  20. bisco

    bisco cookie crumbler

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    new new?
     
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