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only 37 every time?

Discussion in 'Prius v Fuel Economy' started by Hilarysh77, May 4, 2024.

  1. Hilarysh77

    Hilarysh77 Junior Member

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    I've been getting a pretty consistent 37 mpg for at least two years. Very occasionally I go up towards 40. This is regardless of new or old tires, oil change.... The only maintenance minder I get sometimes is something about taking it to the dealer to check on the battery or cooler or something? We may got for a cross country road trip this summer and I'm wondering if it's worth taking to the dealer (maybe not a regular garage?) to see if there is an identifiable problem?
     
  2. Mendel Leisk

    Mendel Leisk Luddite

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  3. Hilarysh77

    Hilarysh77 Junior Member

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    thanks for writing!

    I take long and short trips. It doesn't seem to make a difference. I get a little more if I do solid highway driving for the whole tank, but still below 40, and probably no more than 38. This has been independent of tires-- new, old, just rotated. I calculate the mileage per gallon almost every tank.

    Do you think the maintenance reminder that I need to take it to a dealer to help with battery cooling or something might be a cause? I always ignore that message and then it goes away.
     
  4. Mendel Leisk

    Mendel Leisk Luddite

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    Are you getting a specific warning about battery cooling? That’s been reported before, and IIRC was due to battery fan and/or venting routes being dust clogged. Or fan defective, maybe due to overload with dust.

    any pets regularly in the car?

    Again, knowing the miles might help.
     
  5. Hilarysh77

    Hilarysh77 Junior Member

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    Yes, got the miles, sorry. 117,000 miles.
    It's a 2016, I think.

    Yes, I get a specific message; I shared it with another Prius owner once and they said something is probably blocking something, and made it sound like "oh oh, sorry :(".....

    Would I need to go to a Toyota dealer, or could a regular garage figure that out?
     
  6. Mendel Leisk

    Mendel Leisk Luddite

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    Cleaning the battery fan and ductwork is something you can DIY; takes a couple of hours. OTOH this is a service dealerships have been offering, around $300 USD, and they’re maybe more capable of verifying proper fan running.

    transporting pets can exacerbate this; again, is that something you do regularly?

    Regarding the 117k miles, and this is my personal vendetta: I’d look into cleaning the EGR (Exhaust Gas Recirculation) system, including intake manifold (has EGR passages).

    Sadly dealerships and Toyota aren’t very helpful, will only replace parts, which alone are about a grand, and then there’s labour.

    there’s a few independent shops that’ll do it right, for around $600 USD.

    it’s a relatively complicated DIY, but doable by someone with an array of tools, comfortable to do oil changes and the like.

    I’ve got an “opinion”, that neglecting the carbon build up in the EGR will lead to head gasket failure, typically between 150k and 200k miles.

    anyway, see first 2 links in my signature for EGR cleaning tips. On a phone turn it landscape to see signature.
     
    Danno5060 likes this.
  7. bisco

    bisco cookie crumbler

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    anyone can do the fan/inlet/duct cleaning, if they are willing. do it before the long trip.
    when you get back, look into the egr circuit cleaning, very important.
    what make and model tyres?
     
  8. rjparker

    rjparker Tu Humilde Sirviente

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    As someone who actually has a Prius v I will offer the following:

    1. Low octane gas will reduce mpg maybe 2 mpg. Nothing to do with top tier additives. Some low octane generic pipeline suppliers are used by many retailers who may or may not add top tier additives. You can’t believe the 87 octane rating at some stations.

    2. Driving faster than 60 mph on a regular basis will impact the nominal 39 highway epa number. A v has a higher numeric final drive ratio to handle more weight. That gear ratio reduces the epa number no matter what but really impacts mpg at higher speeds.

    Where I live, the two lane state highways are typically driven at 60-65 mpg. Mpg is ok. Any freeway is 75-80 mph which reduces mpg to 38 mpg overall or less. A mix of highways will get about 40 mpg overall.

    3. Driving habits and specifically braking makes a difference. Reasonable acceleration and gradual braking such that regen is 95% of the braking adds a couple mpg depending on route and number of slowdowns.

    4. A weak hv battery will cost you 4-5 mpg. Weak meaning close to replacement, often creating fast discharges in a stopped in Ready AC on situation.

    5. Tires make little difference as long as they are a quality brand like Michelins. The standard size is already bigger than a hatchback with more contact patch. Proper inflation minimizes the contact patch. I now run Michelin Cross Climate2 (ice storms now routine in Central Texas winters) with no mpg impact.
     
    #8 rjparker, May 6, 2024
    Last edited: May 6, 2024
  9. Mendel Leisk

    Mendel Leisk Luddite

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    Dr Prius app is good for battery assesment, works with Carista bluetooth OBD dongle.
     
  10. Hilarysh77

    Hilarysh77 Junior Member

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    Oh my gosh I'm just getting to these messages now-- too crazy busy right now!

    Thank you everyone! I'm going to sit down later and thoroughly read them all and look into the suggestions.
    I finally copied down the exact words of the maintenance message:

    "Maintenance required for hybrid battery cooling parts at your dealer."

    Does that still fit with what everyone has said?
     
  11. bisco

    bisco cookie crumbler

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  12. Brian1954

    Brian1954 Active Member

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    Read about this message in the 2017 owners manual.
     
    #12 Brian1954, May 10, 2024
    Last edited: May 10, 2024
  13. Hilarysh77

    Hilarysh77 Junior Member

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    from the 2017 manual:

    ■Hybrid battery (traction battery) air intake vent ●Do not place objects that will block the air intake vent. The hybrid battery (traction battery) may overheat and be damaged. ●Clean the air intake vent regularly to prevent the hybrid battery (traction battery) from overheating. ●Do not get water or foreign materials in the air intake vent as this may cause a short circuit and damage the hybrid battery (traction battery). ●Do not carry large amounts of water such as water cooler bottles in the vehicle. If water spills onto the hybrid battery (traction battery), the battery may be damaged. Have the vehicle inspected by your Toyota dealer.

    So, I'll go out there and see if I can see anything. I pick up and clean enough there shouldn't be something permanently or even semi-permanently blocking it on the outside.... but, maybe on the inside? Or it's been damaged?

    I need an oil change this month (before a big trip) and can see if they see anything.

    Thank you!
     
  14. Hilarysh77

    Hilarysh77 Junior Member

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    Maintenance of the hybrid battery (traction battery) cooling component is required The filter may be clogged, the air intake vent may be blocked or there may be a gap in the duct.  Have maintenance performed on the hybrid battery (traction battery) cooling component at your Toyota dealer.

    ... So, I should go to the dealer, because I really can't do anything fancy myself...
     
  15. Mendel Leisk

    Mendel Leisk Luddite

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    Give DIY a try; the dealership will really soak you, guaranteed.

    I’m familiar with cleaning the hybrid battery fan and ductwork on Gen 3, not so much with Gen 4. Somone here must have done it? On a Gen 3 it took about 2 hours, by far the majority of time dealing with finicky plastic fasteners and catches. I was able to clean the fan without complete removal too.
     
  16. rjparker

    rjparker Tu Humilde Sirviente

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    It turns out the Prius v battery blower cleaning is easier than a hatchback, partially due to the sliding rear seats. The intake is different since it is under the rear passenger’s seat. A simple issue to fix is someone stuffed something under the seat blocking flow.

    But the battery fan and it’s squirrel cage blower is more commonly the real issue if clogged.

    This is a good video on the subject specific for a Prius v wagon.

     
  17. bisco

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    ask the dealers how much, they're competitive. and ask local mechs if they would do it.