Will MPG Increase with a New Hybrid Battery ,Transmission Fluid Flush, and Oil Change?

Discussion in 'Gen 3 Prius Fuel Economy' started by NWEcoCarDriver, Jan 3, 2020.

  1. NWEcoCarDriver

    NWEcoCarDriver New Member

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    I just bought a 2010 Prius V with 127,xxx miles on it 72 hours ago. Within the first 24 hours of driving it all the symbols on the dash lit up like a christmas tree indicating that the hybrid battery was indeed needing replacement. I took it to the Toyota dealership and they did a new car inspection and diagnosis. They tell me that the car is in great shape, but needs a new hybrid battery, a software update from the recall, and a transmission fluid flush. I authorize all work as the hybrid battery was in warranty with a whopping 27 days left in the 10 years. The hybrid battery would've been over $4,xxx to be replaced by the dealership without the warranty.

    What I want to know is what kind of mpg's I should be getting with this car? The trip said 38 mpg for the life of the car. I'm wondering since the hybrid battery was replaced and the transmission fluid and oil were changed, will the mpg improve? It's got the standard factory 17" wheels and Michelin tires on it now.

    What mods can I do to the car to get better mpg?
     
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  2. Tideland Prius

    Tideland Prius Moderator of the North
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    Congrats on your purchase! Yes mpg will improve but since you just got the car, you won’t have a baseline for your type of driving. You should be able to get near 50mpg in the summer with city driving and 45-46mpg in the winter. Careful driving will net even higher city mpg in the summer (I’ve seen as high as 57mpg over a tank).

    Check the records to see that the coolant has been changed at 100,000 miles (there are two coolant systems - one for the engine and one for the inverter).

    Other than that, you should be good to go (oh and ensure the oil was last changed at the regular interval).

    The 17”s will knock 1-2mpg off compared to the 15” wheel models so I think my estimates are reasonable.

    mods? Well an engine block heater will help reduce the mpg hit in the winter as the engine warms up (and it’s cheaper to use your electricity to pre-heat the engine instead of gasoline). A warmer engine faster means accessing EV mode sooner.

    You can also use foam pipe insulation (cut lengthways) to block the lower grille/air dam to reduce engine heat loss. If you don’t have a scan gauge to monitor temps, the rule of thumb is 50% block below 50°F and full block below 32°F daytime highs.

    Ensure your tire pressures are kept up at least to factory spec (some of us run 1-2psi higher).
     
  3. sam spade 2

    sam spade 2 Senior Member

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    Forget modifications, except maybe for a block heater if you live where it is cold.

    Just be sure that you have the equipment you are SUPPOSED to have.
    LRR tires at the right pressure.
    Using the right oil.
    Brakes not dragging.

    Oh......and ask the shop how old the 12 V battery IS.
    If more than 5 years, replace it too.
     
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  4. fuzzy1

    fuzzy1 Senior Member

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    I don't remember Gen3s having a lifetime MPG display. Instead, they have Trip A and Trip B MPG and distance. When an MPG is showing, look at the displayed Trip meter, that should be the distance over which that MPG applies.

    But just erase and reset both of them, neither is any longer relevant. They are specific to the previous driver's driving patterns, trip or commute routes, and speeds. And to the prevailing weather during that time.

    Reset them and start tracking your own personal MPG under your particular routes and driving patterns, that is what will matter. I use one trip meter for a whole fuel tank, the other for each day's MPG. The latter helps highlight how MPG starts out very lousy on a cold engine (not just a Prius, but any fossil fuel engine), then improves with warmup and distance.

    A new traction battery may help, but fluid and filter changes shouldn't have a noticeable impact.
    The most important "mods" are to driver behavior and style. Read up on how to drive for efficiency.

    Also, check out these threads:
    Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new | PriusChat
    Why mileage gets worse in winter | PriusChat

    There are plenty more threads available.
     
  5. jerrymildred

    jerrymildred Senior Member

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    I was about to say, "Take it back!" till I saw that the battery is still under warranty. Whew!! Congrats.

    On the transaxle fluid, it's due for a change. There is no such thing as a flush with the Prius transaxle. It's easier than changing the motor oil other than maybe the removal of some extra plastic.
     
  6. Tideland Prius

    Tideland Prius Moderator of the North
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    Question for everyone. Do you recall if the Gen 3 has some sort of learning software (like how regular automatics have fuzzy logic and can learn the driving style of the owner and shift accordingly). If so, we could suggest disconnecting the 12V to reset the ECU and get him back to factory settings.

    Speaking of factory settings, you can set the nav (if equipped) back to factory settings by going into the settings menu.

    Also, press and hold the two outer buttons on the Homelink mirror (1 and 3) to delete the programs so you can add your own.
     
  7. fuzzy1

    fuzzy1 Senior Member

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    I have no recollection of any such driving style memory in a Gen3 Prius.
     
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  8. TMR-JWAP

    TMR-JWAP Senior Member

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    Only 127k miles...that's great. I can't believe no one has suggested getting an OCC installed now while the engine is relatively young, before it causes issues with the EGR components...that's a pretty hot topic for the Gen 3s, especially the earlier ones. If I found a nice low mile 2010/11, I'd be all over that like white on rice.
     
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  9. Tideland Prius

    Tideland Prius Moderator of the North
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    Thanks.

    Should’ve sold you mine lol. 100,000 miles, loaded Tech pack. Clean interior (as in, you can still see the grain on the leather steering wheel. It’s not shiny like other leather-wrapped steering wheels).
     
  10. Grit

    Grit Senior Member

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    The last time we suggest that to a new member, someone pointed out that we scared the new member away with the suggestion.
     
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  11. cnc97

    cnc97 Senior Member

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    I have no grille blocking on mine and I’m running mid 40s on MPG with the winter temps. I keep the heat set on 70-72, fan no higher then half way. If outside temp is over 50, I turn the heat off all together. I thought about blocking the lower grille, but the “free” pipe insulation that I had was way too big in diameter, so I gave up on that. Drive it and enjoy it.
     
  12. NWEcoCarDriver

    NWEcoCarDriver New Member

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    I wanted the tech pack.However, I only paid $4750 for mine. Think I did pretty well on this purchase.


    What's an OCC? Why would I want one and where would I get one installed?

    Good call on the coolant. I'll have to look into that or maybe just have it changed anyways.

    I live in an apartment complex, no plugging my car in, in any way easily here. Right now it says i'm getting 40.x mpg, but it keeps increasing. However, this is with an average MPH of 17 as I'm a delivery driver at night time.

    This is all great advice and I have a silly question... How do I track my mpg? Also on one of the screens with the bar graphs what are the little cars meaning?
     
    #12 NWEcoCarDriver, Jan 6, 2020
    Last edited by a moderator: Jan 6, 2020
  13. Tideland Prius

    Tideland Prius Moderator of the North
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    We usually use one of the trip odometers to keep track and reset with each refuel.


    The consumption screen shows mpg in 1 and 5 min interval (toggle between them by holding down DISP on that screen). The leaf cars show you how much you regen in each 1 or 5 min interval. In 1 min, each car is worth 30Wh and in the 5 min screen, each car is worth 50Wh.
     
  14. cnc97

    cnc97 Senior Member

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    An OCC is AKA an oil catch can. It is spliced/installed into the line from the PCV valve to the intake manifold. It separates the liquid from the vapors that occur naturally inside the engine as byproducts of combustion. The liquid stays in the can to be drained at oil changes. The vapor passes thru the can to be burned thru the intake.

    It is speculated that the liquid could be a factor in head gasket failure. The liquid will cause misfire as it gets aspirated into the cylinders. If you remove the throttle body from the intake manifold, you will see where the pool of crud collects. An oily sheen look is ok. A puddle is a bad thing.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe not fuzzy logic, but the few times recently that I've done a complete 12 volt disconnect (for brake work), I'll notice the next two or three startups, there'll be an odd rev-up for the first 30 seconds or so. Like the car's testing and reestablishing some parameters.

    Getting into Oil Catch Can typically requires some owner "involvement". There's various cans, from dirt-cheap to in the hundreds.

    You are "messing" with the car; it technically voids pollution control specs, even though a properly installed OCC is keeping the environment cleaner. You might be failed if you have a regular emissions test, just because it's there. Dealership service departments might not be too impressed either, not sure.

    Your current route between PCV valve and intake manifold is a short, 3/8" ID hose. With an OCC you introduce a LOT more hose, somewhat constrictive couplings, and the OCC itself, with baffles, filter material.

    Most of us are doing this by seat-of-pants, but a mechanical engineer would likely have some reservations. It would take a mechanical engineer to fully understand the ramifications, and lieu, you just over-design, and closely monitor your wonder child. :)

    Oh, and you have to empty it periodically, and once in a while maybe fully disassemble, clean out the innards.

    All that said, if you're into DIY, I would go for it. I did. But be aware: it IS a bit of a rabbit hole. Just finding a suitable mounting location for starters, then how you're going to plumb it, hose diameters, couplings, and on and on.

    If you want to see why you need it, take a look through the throttle body, below there you'll very likely see a little glistening pond. That's the gunk an effective OCC will catch, plus very likely more, the vapourized portion that didn't stop there, made it to the combustion chamber.
     
    #15 Mendel Leisk, Jan 7, 2020
    Last edited: Jan 7, 2020
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  16. abdullah arslan

    abdullah arslan New Member

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    It' not an answer to the question but I want to tell my situation. I bought 2010 Prius on 235k with everything is original except the bumper. After that, I replaced trans-axle fluid and oil, and last week it had the second oil change with Mobil 1 Full S Extended High M. I also cleaned the air filter. As a result, the car, is now on 245k, started to accelerate faster than before and I can feel the increase of torque significantly. And it gets 43mpg in the temperature of 30s.
     
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