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getting 21mpg

Discussion in 'Gen 2 Prius Fuel Economy' started by misterdean, Jan 10, 2017.

  1. misterdean

    misterdean Member

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    just bought it. i did do some reading before posting. i know about the cold and using heat. i know about warming up the engine and short trips. so far i've put 77 miles on it. mostly in the city. temps have been 20-30 in my area so ya i use the heat. but 21mpg sounds like something is wrong. i hear this car won't throw up service codes for the hybrid system and the gasoline motor should not come on at all until 30mph, is this information correct? car has no service lights on and drives smooth and quiet. super disappointed and also concerned. i hear something about the pump goes bad and won't throw up a light and people burning up the electric motor. any ideas or suggestions? would be greatly appreciated.
     
  2. wjtracy

    wjtracy Senior Member

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    We have a survey to fill out, but I think you want do a test drive where you warm the car up about 10-15 min and get somewhere you can do 50-55 MPH level for 10 minutes or so ...you want to see the MPG bars in the display get to around 50 MPG at 50 MPH, maybe 45 MPG in the cold. Maybe get a pic of the display at that point. The display holds 30 minutes of MPG bars.

    As low as 20 is pretty bad all I can think is bad hybrid battery or something, but its hard to say.
     
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  3. Moving Right Along

    Moving Right Along Senior Member

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    Is most of your driving in heavy traffic jams for short distances? I had a trip today where I was probably around that MPG number - it took 45 minutes to drive 3 and a half miles! But if you've got any amounts of driving where you can get up to 40 miles an hour or more for a few minutes at a time, you should be better than that. Most of my trips to the grocery store (less than 5 minutes driving, 35 miles per hour speed limit, 5-25 degrees F) end up around 25 MPG if it's from a cold start, but anything longer is typically 40 MPG or more (35 MPG when below 0 degrees F)

    The engine comes on almost immediately in cold weather for me. On Sunday, when it was 9 below zero, it was going like gangbusters trying to get the car up to highway speed. In my limited experience with above freezing weather so far (only had the car a few weeks now), the engine on my car doesn't start until the car goes above 10 MPH or so from a stop.
     
    #3 Moving Right Along, Jan 10, 2017
    Last edited: Jan 10, 2017
  4. misterdean

    misterdean Member

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    i test drove on the highway. i reset the trip display when i got in it. got it up to 90mph but mostly stayed around 30-50 without any stop and go. was roughly 20 minute trip. the drive home was another 20 minutes. should be enough time for it to warm up. wasn't even cold that day. i was watching the display when driving. even when barely touching the petal it shows the gasoline engine assisting. i found the consumption display and it's always hovering around 20mpg. based on what other people are saying the calculations are not as accurate and calculating yourself at the time of tank fill and the display usually reports a little better than what you actually get. if this is true i might be getting 18mpg. i know driving conditions effect the efficiency but it sounds like something is wrong.
     
    #4 misterdean, Jan 10, 2017
    Last edited: Jan 10, 2017
  5. Moving Right Along

    Moving Right Along Senior Member

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    Hmmm... In that case I'd agree that something seems off. According to Fuelly, the lowest MPG reported for a full tank of gasoline on a 2006 Prius was 31 (when outliers were removed). So if you're getting lower than that for a significant number of miles, there's likely a problem.

    If you switch to the "energy" view where it shows the battery level, does the battery level go up and down quickly between 2 bars and 7 bars? And what's the battery level when you first get into the car in the morning?

    If the battery level is low (2 bars) in the morning and/or goes up and down between 2 and 7 bars while you're driving, your traction battery might be going bad. If the battery level is steady (typically between 5-7 bars), then it's something else.
     
    #5 Moving Right Along, Jan 10, 2017
    Last edited: Jan 10, 2017
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  6. misterdean

    misterdean Member

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    just went outside to do a cold start. battery was 3 bars below full and after a few minutes it went up 2 bars. when driving it always hovers around 2-3 bars below full.
     
  7. valde3

    valde3 Senior Member

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    Sounds like hybrid battery is in good condition. You really need to test your MPG on highway.
     
  8. misterdean

    misterdean Member

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    i almost never drive on the highway. even if i only drive in the city i should be getting more than 21mpg, correct?

    any way to test if the electric motor is working properly?
     
  9. bisco

    bisco cookie crumbler

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    congrats and welcome! how many miles on her?
     
  10. Moving Right Along

    Moving Right Along Senior Member

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    Based on what you've said so far, your car is running and the battery is healthy. If there was a problem with the electric motor, your car wouldn't move. I'm sure that's fine.

    It would be useful to get an idea of your highway miles per gallon just to see what your car does when there are no stoplights and it can go for 10-15 minutes or more at consistent highway speeds. The difference between your city and highway MPG can show if your low MPG is from your commute or something is wrong with the car.
     
    #10 Moving Right Along, Jan 10, 2017
    Last edited: Jan 10, 2017
  11. PA Prius

    PA Prius Active Member

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    This sounds like an odd highway drive that would not result in optimal mpg-- up to 90 mph and mostly between 30-50?! Are you driving in deep snow? Hopefully not at 90 mph. I can not imagine any other way to get 21 mpg unless you are making most short trips of less than a mile. We have almost 230,000 miles on our '04 and the worst tank we ever had was in the upper 30's.
     
  12. PA Prius

    PA Prius Active Member

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    Extremely low tire pressure could also be an issue.
     
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  13. misterdean

    misterdean Member

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    2006 with 112K.

    i had it on the highway for 15 minutes during the test drive. consistent 30-50 mph with no stop and go. i understand what you guys are telling me about see what your mpg is on the highway. but i want to stress that even in the city i should be getting more than 21mpg, right?

    the car runs and drives smooth and quiet. it's super clean too. bought it from a japanese dealer. said they only accept trade in from japanese customers cause they are super fussy about condition and take good care of their cars. they told me they bring all their vehicles in for inspection. i called their service guy. told me he replaced fluids checked belts and brakes. asked if any kind of testing or inspection of the hybrid battery or electric motor. said no we don't have the equipment. i called toyota. told them no service lights and car drives good. asked them what they can do. they said not much since no lights and nothing to reference as a problem besides the mpg. said they can look at it for $122. asked what they would be doing. said even they don't have a way to test the motor or battery. they would just be doing basic inspection of wheel wells and doing something called a system health check that only toyota can do. the guy i talked to also owns a prius. he said he gets around 32-35 in the winter. he also agreed that if his vehicle was getting 21mpg he would be concerned.

    what else can i do or test? right now i feel like my hands are tied and their is nothing i can do but wait for warmer weather and take it on the highway.
     
  14. wjtracy

    wjtracy Senior Member

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    The first step is always to check the 12v battery, by the way.
    There are guidelines posted here to test.
    There are also MPG guidelines/survey. We need to know tires etc.
    Its hard to say much on the first partial tank.
    Unless there is a serious issue you may need a couple tanks for the system to calibrate itself if power was cut off. Hope you are in USA units not metric kpl.
     
  15. Moving Right Along

    Moving Right Along Senior Member

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    In addition to low tire pressure, things like a dirty engine air filter, poorly performing spark plugs, or clogs in the fuel system could affect your fuel economy. Don't know if the Toyota dealer would include looking at that stuff in their System Health Check, but I'd guess so.
     
  16. misterdean

    misterdean Member

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    no snow. on highway i stayed around 50. only went up to 90 briefly just to make sure it would drive as expected. the 75 miles i put on it wasn't a short trip. it was the test drive and the drive home. car was running for roughly an hour. fluid/filter change and basic inspection of belts brakes etc was done by the dealer. no spark plug change though. i will look in to the tire pressure and 12v battery. anything i can do to test or remedy clogs in the fuel system?
     
    #16 misterdean, Jan 10, 2017
    Last edited: Jan 10, 2017
  17. misterdean

    misterdean Member

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    what do you mean?
     
  18. Moving Right Along

    Moving Right Along Senior Member

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    When you were doing the test drive, what's the highest MPG the consumption graph showed for a 5-minute period? Typically, if I'm driving for an hour on the highway, my consumption graph will show 40s or low 50s unless the temperature is below 0° F.
     
    #18 Moving Right Along, Jan 10, 2017
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  19. misterdean

    misterdean Member

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    i wasn't looking at the screen with the "average" mpg cause i was not aware of it. but i was watching the screen that shows the "current" mpg. and to be honest, the numbers it was showing on the display was all over the place. i did see in the 30-40 range, but after driving it more i realized when you take your foot of the pedal that bar shoots all the way up to the cap of 99mpg. at first i assumed since it's already rolling and i'm not giving it gas that's the reason i'm seeing it hit the maximum number displayed. but now that i found the screen with the "average" mpg of 21 i find the difference between what the 2 screens show unusual and i'm wondering if you guys see the bar shoot all the way up when you take your foot off the pedal.
     
    #19 misterdean, Jan 10, 2017
    Last edited: Jan 10, 2017
  20. Moving Right Along

    Moving Right Along Senior Member

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    The numbers on the Energy screen (the one with the engines, wheels, arrows, and battery level) are "instantaneous MPG" or supposedly the miles per gallon you're getting at that moment. While it can give indications, what really matters is the average miles per gallon. On the Consumption screen, it shows your MPG average for each 5-minute section of your drive. Typically, the first 5 minutes of a drive from a cold start will be 25 MPG or lower and then the next 5-minute section and the rest will show in the 30s, 40s or 50s depending on conditions. The only time when I've seen a trip of longer than 10 minutes have MPG stay or repeatedly go back under 25 MPG was when I got stuck in big traffic jams.
     
    Data Daedalus likes this.