My how many miles until the flashing light comes on is always different

Discussion in 'Gen 3 Prius Main Forum' started by Freeze Time, Jan 2, 2020.

  1. Freeze Time

    Freeze Time Junior Member

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    What I mean is that when I fill up the car with gas, there is an option to see just how many miles it estimates you will be able to drive until it reaches zero. It used to be around 515 but I have noticed over the past couple of months that sometimes it's at 475 or 490 or 480 etc. It has not shown 515 in a long time. What is going on exactly? I know it's a full tank each time because the gas pump stops and I can see how much gas has been pumped into the car knowing how much I still had in there. So for example, if I got the noise letting me know the meter is now at 0, I have about 2 gallons left. I then go to the gas station and a little over 9 gallons are in before the pump auto shuts off.

    Is there something wrong with my mileage or is this normal? I'm about to go get an oil change(last time my mechanic said I needed synthetic so I am getting it again)and wanted to know if I should tell him about this to see if there are any issues.
     
  2. bisco

    bisco cookie crumbler

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    you're average mpg's are dropping. it uses past history to estimate dte

    cooler weather and reformulated gas can do that. tires pressure and model are important.

    clean filters and etc.

    how many miles on her?
     
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  3. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Some fresh quotes for @Grit?

    Seriously, there is nothing wrong with the car, and don't send a pro mechanic on a wild goose chase. Unless you've just won the lottery I guess.

    The one thing that concerns me: if you're regularly running the tank down to flashing refill warnings, you may eventually win the out-of-gas-on-the-freeway lottery, which can get expensive: the Prius in particular gives little warning, may seriously deplete the hybrid battery.
     
  4. Freeze Time

    Freeze Time Junior Member

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    I recently got 72.4 miles to the gallon going about 43 miles mostly freeway driving. Still have no idea how I did that that but that's what the car told me. I have 43,000 something on it I think. I live in Southern California. The weather here is like maybe low 60's in the winter. The tire pressure light has not come on and I put air in the tires a couple of months ago.

    That's already happened to me once. It was like 2 months after I bought the car so I was still getting to know it. My insurance sent a guy out and he put like 2 or 3 gallons in the car and it started right up. The light flashing means you have about 2 gallons or so and that's plenty of gas and time to go fill up.
    If there is nothing wrong with the car, why is it not showing up at 510-515 anymore?
     
    #4 Freeze Time, Jan 2, 2020
    Last edited: Jan 2, 2020
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  5. bisco

    bisco cookie crumbler

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    see my edit
     
  6. Freeze Time

    Freeze Time Junior Member

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    I did and I thought I answered your questions. My mechanic does a whole inspection, tire rotation and all that with the oil change so I will see how the car reacts after all that.
     
  7. bisco

    bisco cookie crumbler

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    sorry, you did. i was just mentioning a few things that can cause reduced mpg's.
     
  8. fuzzy1

    fuzzy1 Senior Member

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    Because it is now winter, and your MPG drops in winter, and your DTE display uses your recent average MPG to blindly forecast the remaining distance. There is nothing abnormal about this.

    Why mileage gets worse in winter | PriusChat
    Don't bring up this item, unless you want to test his honesty. It will only give him opportunity to needlessly lighten your wallet and make his next boat payment.

    MPG is much more highly variable, depending on conditions, than most people realize. Especially in the short term. Cold outdoor temperatures, cabin heat, water on the road, wind, engine warmup from cold starts, short trips, hill or mountain climbing, winter fuel blends, all burn more fuel. And tilts on hills or sloshes around corners can keep some fuel away from the pump inlet, making some of that 2 gallon "reserve" inaccessible.

    So that "plenty of gas and time to go fill up" can run dry or fail much earlier than expected. As you have already experienced.
     
    #8 fuzzy1, Jan 2, 2020
    Last edited: Jan 2, 2020
  9. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    Was this round trip?
    This was probably going downhill. Even a slight elevation drop that you can't see can give you a bump up in mpg.
    Make sure your tires are 40 psi or even 42/44 psi. Measure it. Then do a 20-30 mile round trip and see what your mpg is.

    Mike
     
  10. Freeze Time

    Freeze Time Junior Member

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    I get that but again, I live in Southern California. It's currently 64 degrees. I don't really have a winter or cold weather. If everyone here experiences this with their Prius, then I have nothing to worry about.

    One way. I make this trip a lout and there isn't too much downhill at all. I usually get 50-55 MPG on this trip but I'm not sure how I was able to get 72.4 at all. The most I've ever gotten before that was 63. I am pretty sure that's what my tires were at when I last put air in them but I will check again. I'll go and get an oil change tomorrow. I'm still salty that I need to spend extra for synthetic oil but if that's the cost of owning a Prius, it's worth it.
     
  11. fuzzy1

    fuzzy1 Senior Member

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    Is it colder now than during the rest of the year? I thought that even SoCal experienced winter temperature reductions.

    Does SoCal have more rain or wind in some seasons than others? I thought it did.

    Does California have a winter fuel blend? Yes, and it has lower energy content than summer blends, producing lower MPG.
    Winter blend gasoline on tap for California; will prices go down?

    So while you may be exempt from part of that 'winter' list, you are not exempt from all of it.

    Synthetic was a requirement from Day 0 on the Gen3, i.e. April-May 2009, because there was no non-synthetic 0W-20 available at that time. There may be now, but those of us long-time Gen3 owners have long been accustomed to synthetic.
     
    #11 fuzzy1, Jan 2, 2020
    Last edited: Jan 2, 2020
  12. Freeze Time

    Freeze Time Junior Member

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    Yes, it is a little cooler than normal. It's usually in the 70's here. You answered your own question about California winter blend as I have no idea. I have a 2015 Prius. If synthetic is better for my car or my car requires it, I will get it. I haven't checked my owners manual but it seems most here are in agreement about it.
     
  13. bettergolf

    bettergolf Active Member

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    If you didn't use synthetic, that would be fine but you would need to change the oil more often, so I think the price of a synthetic oil change per the mileage it lasts comes out about the same. I also have a 2015 and I change around 7-8k miles even though the owners manual says 10k.
     
  14. Freeze Time

    Freeze Time Junior Member

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    I am going to Vegas next week as I go every year for CES. There is an oil change place there I would go to that charges $9.99 plus tax for regular oil when I used to have my 1998 QX4. I have not taken my Prius there yet. They charge $49.99 plus tax for synthetic. I only go there once a year though so if I got an oil change with regular for $9.99, it wouldn't last me all year.
     
  15. Grit

    Grit Senior Member

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    After reading the post I realized, climate change have affected our MPGs!!! We need to switch over to EVs now!!!
     
  16. iskoos

    iskoos Active Member

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    I have no idea how you got 72.4 MPG to be honest with. To me, It is kind of impossible to do unless you coming down the Mt. Everest:)

    And what surprised me is that you actually ran out of gas on a Gen3 Prius. Congratulations. I tried so hard but couldn't. Prius Gen3 has over 2 gallons of fuel in the tank when the fuel gauge beeps at you and DTE shows about 25 miles (mine beeps generally at 25miles to empty point)
    And when I ran it down to 0 miles to go, I put around 9-9.5 gallons in. Once I did go 65 miles after the "0 miles to go" and I put 10.5 gallons into the tank.
    People report driving well over 100 miles after the DTE = 0 point to be able to run out of gas.
    Did you really do that? But maybe Toyota changed something on 2015 models.

    And as for your question, There is NOTHING wrong with your car...
     
  17. Freeze Time

    Freeze Time Junior Member

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    Well, I ran out of gas on the freeway like I posted earlier but I have no idea how many miles I drove before I did as I wasn't planning on driving until I ran out of gas like this Seinfeld episode

    [​IMG]

    I'm glad there is nothing wrong with my car. Thanks guys. I did get an oil change today. $10 more than last year. $63 this time opposed to $53 last time. Inflation!
     
  18. fuzzy1

    fuzzy1 Senior Member

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    Not at all, it is easily done under the right circumstances. Though that means not in common heavy traffic. This is from one of my very old posts:

    "I'm also amazed at what it can do even on hills. This one was a round trip, a mere month into hybrid ownership. Zero net climb, but 3000+ feet gross climb and even some downhill engine braking. But only a handful of stops:
    [​IMG]
    Since then, a few round trip commutes half that distance with more stops, a couple thousand feet gross climb, and a ten hour engine cooling stop in the middle, have reached 76 mpg. Unfortunately, no pics."

    ===============

    I've also done these, but they fell into the "coming down from Mt. Everest" category:
    [​IMG]
    [​IMG]
    The more skilled folks, with time to spare outside of traffic, can do these on level roads.
     
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