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Unbelievable MPG

Discussion in 'Gen 2 Prius Main Forum' started by C Rider, Aug 25, 2018.

  1. C Rider

    C Rider New Member

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    This is my second post, but I bought a 2006 Prius with a bad Hybrid Battery last Sunday for $1200. I had never driven any hybrid vehicle until I drove the car home last Sunday with the bad Hybrid Battery. Yesterday I had a guy who refurbishes Prius Hybrid Batteries come to the house and he swapped out my bad battery for a battery with brand new modules (yes I asked to see the date codes). Today I drove the car to work which is 26 miles and I averaged 57.8 MPG. I did not run the AC this morning because it is starting to feel like fall around here. I then drove the car home with the drivers side window down and when I pulled into the garage I had driven 49 miles and averaged 57.6 MPG. After I got home my wife, children and I drove to dinner with the AC on and I put about another 30 miles on the car and I was still averaging over 56 MPG when I pulled back into the garage. My commute to work is probably 90% highway and 10% city. I noticed around 73 MPH the car almost feels as though it goes into overdrive (I realize it is a CVT transmission and they do not have overdrive) and the instant MPG was actually significantly higher than when I was driving a modest 55-60 MPH. Am I a natural hybrid driver or is this car a freak?
     

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  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Actually, there is an overdrive of sorts called heretical mode.

    Normally Motor/Generator 1 acts as a generator and M/G 2 as a motor, pushing with the engine. In this mode the engine pushes against M/G 1 and the road with help from M/G 2. To get overdrive, called heretical mode, we make M/G 1 a motor pushing against the engine, and use M/G 2 as a generator.

    By pushing M/G 1 against the engine we lower RPMs and allow the throttle to open wider as we can push against M/G 1, M/G 2, and the road. Most automatics do not let you use a lot of throttle without down shifting.

    How the PSD is like a Differential
    Whats Going On As I Drive?

    If this hurts your brain, you know why it was called Heresy!
     
    #2 JimboPalmer, Aug 25, 2018
    Last edited: Aug 25, 2018
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  3. jerrymildred

    jerrymildred Senior Member

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    Welcome, @C Rider and congrats on the great deal. Those are great numbers. Just remember that the Prius computer is a little optimistic. The calculations at the pump will be a little lower than what's on the display. Also, if you haven't seen it yet on the forums, there's a bladder in the gas tank of the Gen 2 Prius that makes fill-ups very inconsistent, especially in colder weather. As a result, you'll need to average mpg calculations over several tanks to really know what you're getting. Nevertheless, 57 mpg is good stuff.

    @JimboPalmer, that's interesting. I just discovered "heretical mode" yesterday. It's pretty weird, but perfectly explains that bizarre anomaly of sometimes getting better mpgs at a slightly higher speed. I see it quite often.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    I don't even try to comprehend the transaxle; it's magic to me. (y)
     
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  5. sam spade 2

    sam spade 2 Senior Member

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    That's the understatement for the week !! :ROFLMAO:

    Actually it's true of ALL vehicles with an onboard MPG display.
    A manual calculation on the next few fillups would be in order.
    But it likely isn't THAT far off.
     
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  6. Raytheeagle

    Raytheeagle Senior Member

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    Some do that for the whole Prius :p.
     
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  7. VFerdman

    VFerdman Senior Member

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    Congratulations! I too am a first time hybrid owner. Bought my '07 a year ago and am still very pleased with it, though I never ever got numbers like yours. Mine had 175K miles on it when I bought it and about 195K miles now. I am getting mid-40's over a year of driving. I consider that really good as I just mostly drive the thing without trying too hard to eek out an extra MPG or two. I do not use A/C too much because I do not go on highway a lot and I really like summer air in the cabin. Not too crazy about processed AC air, but I do use it on highways and on really super hot and humid days. I find AC premium to be smaller than winter heat premium. You will notice that in the winter the economy decreases drastically. The engine needs to run more to keep itself (and you) warm. Still gets low 40's for me in the winter and high 40's low-50's in the summer. You will find that sometimes those numbers on the screen are off and sometimes they are right on the money. Hopefully you got a really good car that can do mid to high-50's, but I think it may be just the adjustment to the new battery, etc.

    If you don't mind my asking, how much did you pay for the battery refurbished with new modules? It's a hot topic around here, understandably.

    Enjoy the new hybrid experience. It's really a game changer for someone new to it. And gen 2 Prius in particular is an excellent implementation of the idea. It's a very robust vehicle with very few (and well known and documented) issues. Wait till you see the (lack of) brake wear on this car!
     
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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Our 2006 Civic Hybrid's mpg display (actually liters per 100 kms, to split hairs) was either spot-on or slightly pessimistic. It can be done.

    But yeah, our Prius is a compulsive liar. By roughly 7.5% on average, last time I checked. Honest...
     
  9. C Rider

    C Rider New Member

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    Thanks for all the great information. Jimbo I believe that is what I am experiencing. I figured since this car is a hybrid it would do best at 55 MPH.

    Vferdman- I paid $1900 and the man who did it drove 100 miles to swap my hybrid battery for the one with new modules (date codes from 2018, gen 3 modules). He offered it to me for $1750 if I wanted to drive to him and install it myself. He got to keep my old hybrid battery in either instance. I pulled records from Toyota's Website and the car was taken in and diagnosed with a bad hybrid battery two years ago by the second owner. It appears he then had the battery replaced (with a reman Falcon Battery)and sold it to the college girl I bought it from. The reman battery only lasted two years / 16k miles.

    I feel like I did good on the car. It appears to have a good service record with Toyota and instead of paying $3500-$4500 for a similar Prius I got this one for $1200 +$1900 = $3100 and now I have a brand new battery vs one that someone may have replaced two modules with E-bay or junkyard modules. I figure another bonus is if I do have any major problems with the car I can still sell the Hybrid battery in a few years for much more than someone else is going to get out of their 2006 battery. I am very frugal if you can't tell. Prior to the Prius I had a 2003 Toyota Matrix, it was the year that had a ring / oil control issue. It was starting to burn 1 qt. of oil per 300 miles. I also had a Toyota Echo. The Echo was a great little economy car and it is still still in the family with 190k miles.

    I have read about the bladder in the gas tank. Did I mention I am frugal? I buy groceries and gift cards from Kroger with my American Express Card and get 6% back from American Express and the fuel points. I then take my car (Toyota Matrix) to Kroger with 6 VP Racing Gas Cans in the hatch and I fill up the tank and the gas cans. I then refill my cars in the comfort of my garage until I run out of gas again. So in theory I save $35 every time I fill up my tanks. What I am getting at here is between my car and my wife's car I only fill up my car with a gas pump twice a month. I won't be able to fill up the Prius and do the manual calculation unless I am not frugal for a few weeks.
     
  10. fuzzy1

    fuzzy1 Senior Member

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    Do note that slight downhills and tailwinds, even those too small to be perceptible, can very noticeably boost MPG. Your only clue may be a disappointing MPG on the return trip slightly uphill or into the headwind (or breeze).
    Not my '14 Forester, its MPG display is essentially spot-on, when compared to milepost or GPS miles.

    When measured against the odometer, it does appear slightly optimistic. But the odometer itself is 1.8% pessimistic, following that spate of class action lawsuits about warranty fraud from overreading odometers. After adjusting for that intentional bias, its MPG display is quite accurate.
     
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  11. PriusCamper

    PriusCamper Senior Member

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    What was the air temperature you're driving around in? Also were the roads mostly newer pavement? This is a great time of year for good MPG. If it gets too hot and A/C use and overall inefficiency sinks in and MPG drops... Likewise, in Winter weather MPG will be way lower. My best MPG in my Prius is always on California HWYs when 70-80 degrees temp out. They have really smoothe asphalt standards in California. In the PNW in winter on the other hand MPG is down in the mid 40's.
     
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  12. jerrymildred

    jerrymildred Senior Member

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    LOL! I did almost the same for a couple years till our grocery store dropped that perk. But they had a 20 gallon limit, so I used two 5-gallon cans.
     
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  13. C Rider

    C Rider New Member

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    It has been 70-77 degrees the last two days. It is Ohio, no road is new. Our state flower is the construction barrel. When I travel to the southern states I am always amazed by how smooth the roads are. Around here they just get the roads semi repaired and then we get our first snow. Today I drove with the air on most of my trip because my wife made me and it was raining. I would say todays driving was 70% highway 30% city. I live in a valley so maybe I have a little benefit that the ICE is warming up while I get out of the valley and when I go back home I can essentially coast the last 1/2 mile or more. Maybe it is the third generation modules.
     

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  14. PriusCamper

    PriusCamper Senior Member

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    A dozen year ago during the gas price crisis I read about some folks like y'all... They filled up all the one gallon water jugs they could find with gasoline and stored them in their closet where their natural gas powered water heater was. Those darn pilot lights!!! Ruined all their gas, the whole apartment complex too! :)
     
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  15. audiodave

    audiodave Active Member

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    Especially along the coast. My best MPG in any car I've driven.

    Posted via the PriusChat mobile app.
     
  16. kens97uber171

    kens97uber171 Active Member

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    There is a great YouTube Channel. Weber Auto. He runs a automotive college that focuses on hybrids and EV's and does some great videos on theory of operation and also in-depth disassembly and description of how it works. A bit technical but not bad. Take a look if your interested.
    This video is shorter and gives a basic overview on how the 2nd gen trans works.



    This one is a deep look including disassembly..




    Mechanically they are not that complicated... And there are no wearable items I side them.

    change your trans fluid every 60k. And they should last a very long time..

    That's not a difficult job to do yourself... Don't let a shop charge you too much. Takes 30 min or so..

    Enjoy.. hope it helps.


    Posted via the PriusChat mobile app.
     
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  17. C Rider

    C Rider New Member

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    Thanks for the info Ken. While I reading the forums I seen many people ask if they should invest money in a Second Generation Prius on new hybrid battery. I was quite surprised how many people said, "no just get another one." One person said if the transmission goes out it cost $5k. I almost sold mine before I did a little research and found out more than likely it should outlast the car. I was able to enter my Vin number on Toyota's Website, and it appears the first owner did really well keeping up on maintenance.
     
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  18. Mendel Leisk

    Mendel Leisk Senior Member

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    I've tried watching those videos, not sure why but they always put me to sleep. :oops:
     
  19. kens97uber171

    kens97uber171 Active Member

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    Salvage yards.. look at Copart. Can find used transmission for few hundred bucks. Same with engines. Obviously labor to install.
    Big thing is to change that fluid.. it's an easy job of you have roll up ramps.. need some hose a funnel and 4qrts of Toyota World standard ATF. $17 at Walmart.
    My car has 245,000 on it... I drained the fluid to be sure... The old stuff looked and smelled the same as the new.

    There are replacement new batteries out there too. Friend been looking that. Found a company selling a pack with new Panasonic modules.. 48month unlimited miles warranty for $2k. Plus I think $700 core.

    Posted via the PriusChat mobile app.
     
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  20. dolj

    dolj Senior Member

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    I would be interested to know who that company is. Hopefully using OEM new, which they would be buying from Toyota for $1620. If not genuine OEM modules, I’d steer clear as the 3rd party prismatic modules are not Panasonic and do not have a good track record for reliability.