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New Prius owner - low gas mileage after gassing up? & other issues

Discussion in 'Generation 1 Prius Discussion' started by sandysalad, Jul 17, 2020.

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  1. sandysalad

    sandysalad Junior Member

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    new first gen (2003) prius owner here.

    I've been looking through the threads and googling but I just wanted to see if anyone could offer advice...

    I got my first gen with 90K miles on it. Was serviced, new hybrid battery in 2018, wasn't really driven much (once every 2 weeks to keep the charge) before I owned it. Now I'm driving it daily (mostly 20 miles or less).

    A couple weeks ago, I took it in to get the a/c freon refilled & the driver belt replaced, and suddenly my mileage has gone WAY down, first to 40-41, then like 38, and then IMMEDIATELY after gassing up the car... 17-20??? No leaks or anything. I know the tires need to be changed, and I'm planning on doing that ASAP. Is it normal to see the gas mileage drop dramatically right after gassing up??

    Thank you for your help.
     
    #1 sandysalad, Jul 17, 2020
  2. Josey

    Josey Active Member

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    That's a computed running average. How many miles is it based on?
     
    #2 Josey, Jul 17, 2020
  3. bisco

    bisco cookie crumbler

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    who did the repair work?

    are you calculating mpg's at fill up by dividing miles driven by gallons pumped?
     
    #3 bisco, Jul 17, 2020
  4. Prodigyplace

    Prodigyplace Senior Member

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    Does the Gen 1 use special air conditioning gas too? I heard of some later models that ruined the system by using the wrong thing.
     
    #4 Prodigyplace, Jul 17, 2020
  5. sandysalad

    sandysalad Junior Member

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    Hi everyone, thanks for the replies...

    - I reset the trip meter right after gassing up. My brother in law who owned the car before me said that it can kind of mess with the readouts when you do this, since the computer isn't very complex. He said on the best days you can usually get mid 40's readouts.

    - Have not driven it more than 1 mile since last gassing up, it's just been parked.

    - I got the repairwork done at a mechanic that has good reviews and said they work on Priuses (they had a couple in there when I went).

    - I do not know what freon they used to fill the a/c. I read that you can use regular or the special toyota freon. I believe they also flushed the a/c. I can ask them.

    - The car is showing no other symptoms or problems. I know the alignment is slightly off (also will get repaired, but not undriveable according to mechanics) and the tire pressure could be re-upped.
     
    #5 sandysalad, Jul 18, 2020
  6. Nelsonprius

    Nelsonprius Junior Member

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    No mileage reading is accurate after 1 mile, more like 50 miles or 1 tank
    Ignore it
     
    #6 Nelsonprius, Jul 19, 2020
    orenji likes this.
  7. Josey

    Josey Active Member

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    Holy cow.

    A car's mpg - any car, not just a Prius - is not a steady state thing. It's an overall average over many miles. Hammer the pedal and your mpg sinks really low, Prius or otherwise. Come off the pedal and let momentum or gravity or whatever carry you and your mpg goes way up. Your mpg - regardless of the car - is changing every second you are driving mostly depending on how hard you're hitting the pedal.

    Do you want a thrill? Go to the top of the largest hill / mountain in your area. Reset your mpg counter and go down the hill / mountain while using the minimal amount of accelerator pedal - none if possible. Gravity is your friend. Your display will give you 99 mpg. (But it will be higher than that - there's only so much you can do with 2 digits).

    After that if you want to be bummed out, when you get to the bottom reset your mpg counter and drive back up. Do it fast with a lot of accelerator pedal. Now you'll be down to 17 mpg - but probably less.

    This is the way that mpg works. As you drive your mpg is all over the map. Hit the pedal and it dives. Come off the pedal and it shoots up. This is why you're looking for a very long term running average. Until you're looking at 1000+ miles, don't assume that you know what you're getting in terms of mpg. Want more? Stay lighter on the pedal.
     
    #7 Josey, Jul 19, 2020
    Prodigyplace likes this.
  8. orenji

    orenji Senior Member

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    Short trips will not provide you with high MPG readings. You need to drive it to get true readings.
     
    #8 orenji, Jul 19, 2020
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  9. Prodigyplace

    Prodigyplace Senior Member

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    My 2017 will read 199.9. Conversely, on a cold morning, I have seen 0.1 mpg when I reach the end of my driveway. I have a setting that shows mpg fir the current trip too.
     
    #9 Prodigyplace, Jul 19, 2020
  10. sam spade 2

    sam spade 2 Senior Member

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    THIS.
     
    #10 sam spade 2, Jul 19, 2020
  11. Josey

    Josey Active Member

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    I'd love that many digits - the Gen1 only gives 2 plus one decimal. And that's only the running average. The moment to moment is just a 0-100 bar.

    Cold weather does drag things down. Longer warm up times, on average a richer fuel mix. Stuff like that. And, of course, if you just start the car and let it idle while warming up that's actually zero mpgs.
     
    #11 Josey, Jul 19, 2020
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