Worst first tank ever...

Discussion in 'Toyota' started by jab, Apr 4, 2008.

  1. jab

    jab TreehuggingDirtWorshipper

    I have been getting to know my Prius the last week and a half. Excited with my display's 39.1 mpg I thought I would top off to add a tank to my mileage log today. To my horror when I do the math of 148 miles and 5.374 gallons my calculated FE is 27.5 mpg!

    I know it has been cold and I have been not the best hyper miler transitioning from a manual to an automatic, but I am really bummed! I am hoping that the dealer really didn't fully fill the tank and that in two weeks when I top off again I will get a more accurate mpg. Can the computer in the Prius be off by so much?
  2. locutus

    locutus MPG Centurion

    Either you didn't get a full fill from your dealer or you ran into some variability between pumps (this one allowed you to put in more than average before clicking off). Or some combination of both.

    You'll find that things even out after several tanks. :) The Prius's display does tend to be a little bit optimistic. Over 27k miles my display has averaged about 2.5% higher than actual, and that's pretty typical of a lot of other owners (please chime in if I'm wrong ;)).

    So don't be too worried. :) And also as we're coming in to warmer weather and you learn more about driving for FE you will leave that 39.1 in the dust.
  3. atlaw4u

    atlaw4u Well-Known Member

  4. jab

    jab TreehuggingDirtWorshipper

    Thanks for the encouragement.! I have not inflated my tires yet, on my to do list this weekend (really it has been too cold for me to play with the tires). Mostly I have been in sensory overload driving the Prius vs my Saturn. I love the Prius, but I don't feel like I know what I'm doing yet... I am hoping to get on to experimenting once I feel more at home.
  5. warthog1984

    warthog1984 Well-Known Member


    How fast are you driving? AFAIK, its difficult to get a Prius under 40MPG.
  6. Skwyre7

    Skwyre7 Well-Known Member

    Keep in mind that the Prius has a bladder gas tank, which is affected by temperature. If it's cold, the bladder shrinks. This makes it difficult to get reproduceable fills.
  7. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Jab:

    ___Some of the members are setting up a Group Meet in the Minneapolis area in May IIRC and if you can make it out, it might be a great time for a clinic!

    ___Good Luck and welcome to CleanMPG too ;)

  8. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Welcome, Jennifer! Wayne is right -- and you are definitely welcome to join us. :)

    If you like, the two of us could meet earlier than that for a basic clinic. I work in Golden Valley and I'm typically done about 3:00 most days. Let me know if you'd like to arrange something.
  9. diamondlarry

    diamondlarry Super MPG Man/god :D

    I had a similar experience when I got my '07 Prius. I don't think the dealers are real concerned with getting it clear full. They probably set the pump on the highest setting so it will shut off faster.:rolleyes:

    Welcome to CleanMPG! I would urge you to make it to the meeting up there as Sean is an excellent teacher. I predict your mileage will skyrocket after spending some time with him.:Banane54:
  10. 99HXCivic

    99HXCivic Well-Known Member

    My worst tank on my HX was my first one too. 2nd week drove better and it was way better.
  11. jab

    jab TreehuggingDirtWorshipper

    Wow, thanks for all the feedback!

    My daily commute is killer for FE, 4 miles with many stop signs at 25-30mph. I live too close to work to make the trip by bus (45min two-transfer trip) and too close for any car to warm up. I wanted an EBH for the Prius, but that didn't happen. The dealer claims that new 2008 Prius and up are not equipped with a frost plug to put the EBH :mad:. If I would have known that before they finished modifications I would have asked them to look at all the #4 Prius on their lot and find one that did. I am sure that since I am female the dealer thought the color would be most important to me and the EBH is not that important since I do not 'need' it, but the EBH was more important on my list than color!

    The great thing is taking the parkway is a beautiful trip with no traffic, once the weather is a little nicer I am going to bike when I can.

    I took advantage of our 66 degree day yesterday to pump up my tires, they were at 30psi. Couldn't remember off the top of my head what I read in the forums here for recommended psi so I went with 45psi. Doing my errands yesterday I am averaging 50.4mpg according to the computer.

    Count me in for the May Group Meet! I hope to be finished with my boards the end of April and will have more time for fun then!

    Thanks again!
  12. lyekka

    lyekka Well-Known Member

    I agree with the others about the tank. I was getting 39 MPG trips in early March when I first purchaced my car. I questioned my driving and found this site. I started by reading the Beating the EPA article and setting my tire pressure.

    My best cold trip after making changes is 64.9 MPG, 10 miles @ 28 F. If I dont beat the old EPA combined of 55 for each trip, I reevaluate my driving. A nice change for only 3 weeks. :) With more effort and learning, I hope to see some 70's soon.

    Thanks to Wayne and everyone else for the great intructions!
  13. diamondlarry

    diamondlarry Super MPG Man/god :D

    The dealer doesn't know what he is talking about in regards to the EBH. The EBH for the Prius doesn't install in a frost plug. It installs in a cavity within the block and doesn't actually heat the coolant directly. They cost about $50 for the part.
  14. lyekka

    lyekka Well-Known Member

  15. jab

    jab TreehuggingDirtWorshipper


    Put in the second tank today; the dealer definitely did not fill up completely when I purchased the car! 44.5mpg computed, 43.9mpg calculated this time. Still under the EPA so I'm going to have to work harder! I am really missing my manual transmission! Didn't realize how often I would put in the clutch and coast without thinking about it. ;) I am getting more comfortable with my Prius and learning how to coast by using a light application of the gas petal. Thanks again for all the info and encouragement.
  16. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Jennifer:

    ___Short commutes and the Prius are like water and vinegar but if is any consolation, every other vehicle we could possibly drive will go through a similar hit under that short a distance. Still, 43 + for a 4 mile commute twice a day sounds pretty good for a new owner to me!

    ___I spoke with Mike about the MN meet this evening and everything is ramping up quickly. Expect to see a flyer or two plus some discussion and entry into the calendar. If the Minneapolis area is anything like Milwaukee, the MN Hybrid Group will become one of the highlights of the state in no time :)

    ___Good Luck

  17. Deerebilt

    Deerebilt New Member

    welcome. it will get better fill up in mornings when fuel is cool , set fuel nozzle on slowest setting and dont top off.
  18. Dan

    Dan KiloTanked in post 153451

    Your actually right on track. My first two tanks in the prius were 47 and 41 by display. Until you get at least 5 tanks to start comparing, the calculated values will bounce around a lot. Just enter the pump values in the log and record the display value in your notes. I find the display value is consistently 3% above my calculated values. So if my display reads 50 mpg the calc will usually come out to about 48.5 mpg.

    Just let the break-in take effect and watch the numbers soar. There are some real Prius Pro's here so your in good company.

  19. jab

    jab TreehuggingDirtWorshipper

    Third top-off Friday: 43.6mpg calculated and 45.2mpg computer display. Although below the EPA I'm really happy to be using less gas with the Prius compared to the Saturn, not to mention all the great bells and whistles I have now (bluetooth hands free is amazing I have to say!)

    As has been pointed out my short commute is not the best for beating the EPA. However now that MN has thawed out (mostly) I'm starting biking to work when the weather is nice and that is GREAT for decreased gas consumption :D

    Any news on the MN meetup?
  20. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Hi, Jennifer! We'll be having it Saturday 17th at Michael's Restaurant up in St. Cloud starting at 10AM.

    I need to post a map, etc in the events thread...

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