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Disappointing Mileage

Discussion in 'Gen 2 Prius Fuel Economy' started by JaboJabo, Apr 28, 2005.

  1. JaboJabo

    JaboJabo New Member

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    Hey there,
    I am looking at everybody's comments about the kind of
    gas mileage they are getting and I am kind of bummed.
    I have stopped paying attention to what the onboard is
    telling me I am getting and I am doing the simple math
    of dividing the mileage I have driven by how much gas
    I am filling up with.
    And that comes out to 33 mpg.
    Is there something I am doing wrong?

    OK, now the laughable part. This is the first car
    I have ever owned in my life. I just started driving
    a few months before I got my Prius. I considered
    that maybe I am just a lousy driver but anybody
    who has driven with me tells me that I am a good
    driver (and my friends ain't that polite).

    The only thing i can add is that it seems like the gas
    engine kicks on and off more violently (weird
    wording).
    Do I need a tune up?
    Is this covered under my warranty?

    Any help will be appreciated.
    Jay
     
  2. Tideland Prius

    Tideland Prius Moderator of the North
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    I assume your Prius is quite new?

    If so, the strong shudder is normal. It's prevalent when it's cold and/or when it's new. It will smoothen itself out as the mileage adds up and the engine warms up. Also, your calculated is 33mpg but what does the display say? Your last fill may not have been a full tank.
     
  3. JaboJabo

    JaboJabo New Member

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    Thanks for the reply Tideland Pearl,
    My Prius is only 3 months old but the rumble
    "seems" to be worse. It doesn't get very cold
    here because it's Los Angeles and the sun is
    pretty relentless.

    I am doing my calculations based on
    resetting the odometer when I fill up.
    Then I drive until about 10 miles after
    the last tank indicator is the only one lit.

    I fill up, note the amount of gas I put in
    and divide the number of miles on the
    odometer by that amount.
    I am consistently getting 33 mpg.
    Is my logic faulty?
     
  4. engunneer

    engunneer Member

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    Can you send me (or post) some of your actual numbers (Gallons and miles)?

    Have you read the driving tips guide in the knowledgebase?

    how far do you drive each time you go out (commute length for most people)? Is it especially hilly?

    My first tank was around 40, and my fourth tank is up at 52.2, with about 100 miles left.
     
  5. efusco

    efusco Moderator Emeritus
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    Jay,
    Here's the Knowledge Base Article:
    http://priuschat.com/forums/kb.php?mode=ar...f312bd608376d8a

    It's a little long, but print it out and read it...twice. It should help.

    I'm going to bet that the car is fine and that the main 'problem' is you being new to driving. There are so many little things about driving that eventually become second nature but require concentration and trial and error to a new driver. Your starts are probably not so smooth, your stops are probably not well anticipated and a little herky-jerky. You're probably off and on the accelerator when you're uncertain about upcoming traffic.

    Also, you didn't really tell us about where you drive, how far you drive, etc. If most of your driving is 5-10 minutes to school and then to work then home you're not going to get 60mpg...the car just can't perform well in those conditions.

    Summer will help you. Break in of the car will help you. Learning to be a smooth driver who anticipates stops and traffic and doesn't follow too close will help. Taking 30-45 minute moderate speed trips will help dramatically.

    Ok, did you read the article twice? Then read it again... get a tire guage and check the tire pressures...NEVER trust the dealer or oil change guys to do it right. Check your oil level. Go for a 1 hour drive this weekend and play with the energy screen see what's happening and see if you can start anticipating what the ECU is going to do.
     
  6. finman

    finman Senior Member

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    As the good Dr. said, short trips of 10 minutes or less will get you lower MPG...still MUCH better than any car out there...they just don't know it.

    My commute is 12 minutes and in colder temps some of the time. I'm averaging 46 after 24, 000 miles. I know if I drove longer on my commute, I'd be closer to 50+. And on my longer trips that's exactly what I get. It's the darn work commute that brings down the average! Go figure.

    Remember also, in getting the lower MPG, that is the small price to pay for the lower emissions, too. Something the "other" cars can't claim either. Advantage Prius.
    Seems counter-productive, but the car has to burn fuel in order to get cleaner emissions.

    Coast alot, anticipate when you have to stop or slow and get off the gas pedal. This car will glide really well AND keep up with traffic.

    Enjoy the 'zen' of Prius driving. It really is a smooth, calming drive.
     
  7. hdrygas

    hdrygas New Member

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    Anticipating the stops and coasting to the stop is a big thing. I drove to work this morning about 15-20 min coasting to each stop light often not having to come to a compleat stop then brisk acceleration (50-75% throttle) to 38 mph (2 under). I use the cruse control a lot because I have a numb foot and can't feather the peddle well. A pick up behind me got tired of all that and passed me going up hill. Ended up with him right in front of me going in to the parking lot at work. All that acceleration driving over the speed limit and hard breaking and waiting at the lights in front of me had done nothing for him. I parked next to him and smiled. It will get better and I would be willing to bet that at your age you will snatch the pebble from the hand of the best of us before you are done. Driving a Prius is a Zen activity. It will get better. Do check the oil and tires. Many, Many of us have reported oil overfill on pick up of our cars. Think about increasing the air pressure ride suffers a bit but you will get better millage
     
  8. jayman

    jayman Senior Member

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    Jay:

    WRT how you calculate fuel economy, I have to warn you that the bladder in the gas tank can make this a frustrating and error-prone process.

    You're much better off letting the car calculate the average fuel economy as displayed on the MFD.Depending on conditions, your calculated value and the MFD average can be out by up to 30%.

    The only time I got fuel economy as bad as that was near -40. I would imagine if you drive less than 5 miles on a trip, the Prius won't get much better than what you're now getting. But no car or truck will, my 2000 GMC Sierra used to only get 5 MPG under very short trips at -40.

    Hope this helps.

    The "other" Jay
     
  9. Jaguar88

    Jaguar88 Member

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    I live near LA and commute there to work. I usually get about 41 miles/ gallon both computer and calculated. My first tank was about 56 miles/gallon because we had a warm week the second week of April and also I drove on relatively flat ground showing off my new car. But I usually climb or descend 1600 feet on my eleven mile drive to and from work. While it sucks getting 31 mpg on my way home, I get over 100 miles/gallon at 70 miles per hour on my way to work--at least for a 3 mile stretch on the 2 freeway. When the weather warms up I plan to get much better milage, maybe you will too.
     
  10. Jaguar88

    Jaguar88 Member

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    I forgot to say

    You might check your oil, other posters say that an over fill of the oil can reduce milage.
     
  11. JaboJabo

    JaboJabo New Member

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    Thanks everybody for your input.
    This being L.A. there is plenty of stop and start, but also
    I get some nice constant speed flat driving on the freeway
    (I don't have to travel rush hour).
    I have always tried to anticipate the stops and coast to
    a stop.
    Dr Dr... I'll read the faq as suggested: multiple times
    but on first reading, I seem to be in the zone.
    It's warm here in L.A. even when people from L.A. don't
    say it is. But I'll pay a bit more attention.
    I'll check the oil as suggested.

    I guess what I was wondering was if there is a kind
    of "tune-up" that might help.
    As I mentioned, I am a new driver (though I am
    48 years old) and am learning the "feel" of the Prius.
    Perhaps that's why it feels very rumbly when the gas
    engine kicks in.

    Anyway, thanks for all of the suggestions. I'll try them
    for a while and if I still have an issue, I'll be back at you all.
     
  12. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    im sorry but you being a new driver, i dont see it possible that you have already mastered the art of anticipation and speed control. being in a high traffic area as you are now makes it much worse.

    you say its a lot of stop and go and that is what is hurting your mileage. driving slower without stopping is what will help you. if you are driving on multi-lane roads than the H*** with what anyone thinks of your driving. you might find that if coasting or driving at 50% of the posted speed limit, you may find that the traffic lights become the great equalizer. many times i drive on surface streets and i tend to only do ones that have at least two lanes in one direction, i find that this driving gets me where i want to go at the most less than a minute slower than people who sprint from light to light. many times, i end up right behind the same person all the way to my destination.

    try it sometime. make it a goal to not have to use your brakes at all. you may say "impossible" but that means you have given up before even trying. i remember when i first started doing this method. it was tough. gauging my speed took a lot of practice. even though i was in areas i knew very well, i was a poor judge of light timings and would end up being too slow and catching the red light which completely defeated my goal. multiple lights in short distances are also a huge challenge and you will find that poor planning by the traffic engineers will usually make getting through these lights impossible. but if you try, you might find that its not impossible. i cant tell you how happy i was the first time i went from West Olympia, through downtown all the way to my house without having to brake except to turn onto the street i lived on. before that time, i would have told you it couldnt be done. since that time, ive done it half a dozen times. it aint easy and you do have to have a little luck on your side, but it can be done.

    sur
     
  13. bruceha_2000

    bruceha_2000 Senior Member

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    I second the comments on calculating mileage. Since the car is very new, you are better off using the computer MPG than calculating based on miles and gallons put in. Over the life of the car, the latter is the TRUE MPG, but early on it can vary widely depending on how you fill. I have to 'talk' the final gallon in a bit at a time and for that I calculate expected gallons based on computer MPG and miles. I've rarely put in 10 gallons so THEORITICALLY I have 2 gallons left. I've not tested it. :)

    Also ditto the tire air pressure from the dealer or tire place. I had my OEMs put back on after winter, specified 38 front & 36 rear. I was told SPECIFICALLY which tire had which pressure as I put them on the car myself. I checked them the next day when cold. None were the same, the HIGHEST was 33, the lowest 31.

    For MY driving - mostly my commute at 10 miles, with little interstate, plus other side trips here and there of shorter distance, my worst was 34 for 2 weeks when the high temps were single digits, lows double below 0F. It is warmer now - 40s to 60s. My last tank included a lot of interstate at 68 MPH, filled at just over 500 miles and 49 MPG. My current tank is at about 80 miles and CURRENT computer MPG is 50.1. It will drop back to 49.something as soon as I leave work. My first 5 minutes are always low, seemingly about 60% of final tank mileage.

    Remember that the friction brakes engage at 8 MPH or if you are pushing hard enough to slow faster than the electric motor can do it. If you are going to stop at a light, do it gradually rather than all at the end. I try to get to the point where the distance left before I stop is rolling resistance + gravity when I hit 8 MPH. Makes for VERY smooth stops :) ALSO note that if you don't have your foot quite hard enough on the brake while stopped, you will still get energy going to the wheels from the battery even though you aren't moving. If you see those tan arrows. push a tiny bit harder.

    You didn't say, but be WARY of trying to get good mileage by using electric as much as possible. Besides being difficult without an EV switch, running down the battery while moving will only cause it to charge at lights when you are getting 0 MPG.
     
  14. victor

    victor New Member

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    Ive also become a bit disappointed with consumption recently. My Prius is now 8 months or so old and the consumption has increased from 4.4ltr/100km to almost 6ltr/100km.

    At first I thought it was just the winter weather, but as now that is gone, temp yaterday was 28C (i.e. very warm) I cant see its the temprature.

    My driving style hasnt changed, nor has my normal drive.

    In 4000km, the first service is due (15,000km) so I will ahve it looked at, but when I mentioned it in passing when having my summer tyres put back on the tech said it was normal consumption. The official consumption here is 4.5 ltr/100km, so a big difference.

    :(
     
  15. Devil's Advocate

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    It has to be a calculation error, or something seriously wrong.
    I routinely smoke mustangs off the line at stop lights and 90% of my driving is high speed highway driving. My average MPG for the past 3 months (since I got my Prius) has been 45 MPG. Even assuming nothing but short trips and jack-rabbit starts and stops the MPG should never be below 42.
     
  16. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    i experimented with short trips and the worst economy i got was 34 mpg... that was all trips of less than 2 miles and using winter formula gas.

    the experiment lasted only half a tank because i found that even moderate trips of 5-10 miles boosted me up over 40 mpg for the tank
     
  17. GAGendel

    GAGendel Junior Member

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    I've only had my Prius for a little over a week now, but according to the consumption display, I'm averaging just slightly less than 52 MPG with 370 miles on the tank.

    My commute is about 20-30 minutes each way (~14 miles). I do see a decrease in the first half and then it increases during the second half of the trip. I also see a slightly better result when driving from work to home than visa versa.

    Mind you I might be one of those lucky ones. In my previous car (a 96 VW Passat TDI diesel) I was getting 47-50 MPG consistently when the EPA rating was 47 highway. How many people beat the EPA ratings? My Passat driving habits pretty much match my Prius ones.
     
  18. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    those are excelent numbers for the VW... my neighbor has one a 98 i think but she gets no where near that