My 2011 is getting worse mpg than my 2009

Discussion in 'Gen III 2010+ Prius Fuel Economy' started by Little Susie Homemaker, Jul 8, 2011.

  1. Little Susie Homemaker

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    I am not sure what the problem is. I could easily get 48-51 mpg in my 2009 Prius. I just got a 2011 almost 2 months ago, it has less than 1,200 miles & it's getting 38-42 mpg. I still live in San Diego, I drive it no differently than my 2009. I have tried driving it in both eco and normal modes. Is there just a wear in period or something? I don't remember it being like this with my 2009. I'm so frustrated!! Please help. TIA
     
  2. bisco

    bisco cookie crumbler

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    some say there is a break in period, but i never had one on either of my two pri. and 10 mpg's would be an awful lot. google the low mileage threads and see if there is anything in there that might apply to new cars. a quick check of your oil level and tire pressures might be in order. also, if your car sat on the lot for an extended period, your 12v battery might need replacing.
     
  3. cwerdna

    cwerdna Senior Member

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    There is a break in period for the car and the tires. Tire Tech Information - Tire Rolling Resistance Part 3: Changes to Expect When Switching from Worn-Out to New Tires discusses some of the implications of going from worn to new tires of identical make and model.

    It would help to answer http://priuschat.com/forums/gen-iii...-answer-these-questions-esp-if-youre-new.html

    If you drive is mostly city or stop/go, do note that CR got worse city mileage in their testing on the 3rd gen than the 2nd gen. See Most fuel-efficient cars vs. Most fuel-efficient cars.
     
  4. Little Susie Homemaker

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    Model:
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    - What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual) Both

    - What fuel economy are you expecting and why? Expecting at least 50, I could get at least 48 mpg in my 2009

    - What are the approximate outside air temps? mid 70's to high 80's

    - How long are your trips? Varies - some trips are 10 miles to 40 miles

    How old is your 12v battery? What is the voltage reading of your 12v battery after sitting over night? (Method Here) Brand new - 2011 Prius

    Have you had your alignment checked? Any pulling or abnormal tire wear? No

    - How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving? About 1/2 & 1/2, average speed ranges 30-60, not much stop & go

    - What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.) All

    - What are your tire pressures? recommended pressure

    - Is your oil overfilled? (i.e. above the full mark on the dipstick) no

    - Make, model, year, engine and transmission of previous car? (e.g. 08 Honda Civic Si 2.0L 4 cylinder, manual transmission) What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.) 2009 Prius, my old mpg was 48-51

    - What region/state are you in? (if you haven't set your location) San Diego, Ca

    - How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking? I only use the gas pedal when needed, don't brake hard

    - What modes are you using, if any? "normal", EV, power, eco? Normal & Eco

    - Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on? Yes

    - Are you driving using D or B mode? D

    - HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to? AC & auto, set to 76-78

    - Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15). Yes
     
  5. andyprius

    andyprius Senior Member

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    I don't have a 2011, but the typical problem areas are: Does HV charge bars seem normal? ie: almost always 4-6 bars? or better? Does the engine always stop when your foot is off the accelerator? How is the 12V battery level? Do the self check. Does the engine run smooth when accelerating. Could be something really weird like poor contact on the MAF sensor connector. No, no specific wear in period. It is still under warranty let the Dealer check overall operation. Seems like they should be able to check emissions and note proper amount or lack of exhaust gases. :D
     
  6. bisco

    bisco cookie crumbler

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    well done on the quiz, i would let the dealer check it out as andy says. make sure it's no charge when you ask them to look at it.
     
  7. Teakwood

    Teakwood Member

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    That kind of mileage is just not correct. Go to the dealer and ask them to check it out. They may have filled it with 10W-20 oil as opposed to the recommended 0-20 synthetic oil.

    By the way, did you bother to reset the trip odometer when you filled the tank?
    The mileage reading for the first tankful is always skewed low, probably due to shop-floor run-in.
     
  8. john1701a

    john1701a Prius Guru

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    My upgrade resulted in a clear efficiency improvement:

    47.7 MPG average from 118,185 miles with my 2004

    50.2 MPG average from 42,731 miles with my 2010
    .
     
  9. theotherone

    theotherone Junior Member

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    I would check your tire pressure. I would recommend that you keep your tire pressure at a least 40psi (Front) and 38psi (Rear).

    I personally never trust the people at tire shops and/or dealership to check my tire pressure, there are too many inconsistencies! I would also highly recommend that you purchase a good tire pressure gauge (not a pencil gauge) and an air pump. Always check your cold tire pressure at least every 2 weeks or once a month (minimum).
     
  10. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Accelerate harder and see if that helps.
     
  11. JimN

    JimN Let the games begin!

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    Suzie, the Gen3 isn't a Gen2. The performance curve is different & it took me quite some time to get used to it.

    1. Inflate the tires to max sidewall.
    2. Leave the car in ECO & stop warming it up. Boot up & go.
    3. On the HSI try to keep the bar in the left half. The farther to the left, the better. You should see Instantaneous FE off the scale. When accelerating try to keep it out of the red zone as you don't get much more. Try keeping the bar under the ECO lozenge.
    4. I run the AC on recirculate, lowest fan speeds & temp set 76-79F when it is too hot to roll with the front windows cracked.

    It takes practice & is frustrating but keep at it. It took over a year for my 2010 to beat the 2006.

    If you were getting 48 in the Gen2 I don't believe you'll see 50 in the Gen3 without changing your route or speed. I'd expect you to see the same number but be able to get it easier.
     
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  12. HTMLSpinnr

    HTMLSpinnr Moderator
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    For #4, I'd honestly recommend leaving it at auto, and at a comfortable setting on the high end - I use 78˚F in the summer and 68-71˚F in the winter (I live in a mild winter area). While in Eco mode, it forces recirc, and will be smart about the fan speed based on your own comfort. Temperature setting has the biggest impact here. Remember, at MAX A/C w/o ECO mode, the A/C compressor is drawing 1.7kW.
     
  13. ETP

    ETP Ancient sloth foot

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    44psi

    I only run the AC when I have a whining passenger!
     
  14. Insight-I Owner

    Insight-I Owner 2006 Insight-I MT + 2011 Prius

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    Ditto
    Or panting and slobbering. Humans handle heat better than canines can.
     
  15. adamace1

    adamace1 Senior Member

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    The only thing i see wrong is letting the car idle. if you idle if for 5 minutes then drive 10 miles in 5 minutes you might get that low of mpg. Besides that i really can't say what is wrong.

    but alot of people including consumers reports have a hard time getting more than 40-44 mpg city. I drive more on the highway or interstate and the speed limit is 55 by me so that helps.
     
  16. ETP

    ETP Ancient sloth foot

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    I was thinking of placing a cup in the cup holder for passengers to put in a $1 for AC.
     
  17. blacksapphirez

    blacksapphirez New Member

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    it has bigger engine no?
     
  18. bisco

    bisco cookie crumbler

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    yes and it's larger. but all around more efficient. should get at least the same as gen II or better.
     
  19. crash0099

    crash0099 Junior Member

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    Hey Guys,
    I have a 2011 III and I don't see how ETP can go in Florida with out A\C!!! I live 60miles from Tally and this spring we had more 100 degree days than all last year. I have to keep mine on 67 and when I first get in the car fan almost all the way up, until it cools. Now I am new to the Prius and have 4100 miles on it. I learned how to get better MPG from 20 to 35 by watching the gauge and not being in a hurry. I used to try to get up to speed and as quickly as possible (Per Sales Person) in Eco mode and then kick it into EV but I seem to do better by going in to eco and then dropping the accelerator back into the EV side of the gauge therefore going slower. I keep 42 lbs of pressure in the tires. With 4100 miles I have 53.5 mpg on my tank gauge. Even my girl friend can get 48 with out even trying to. So maybe there is something wrong with the car or maybe you need to change the style. Best of luck and take care guys.
     
  20. bisco

    bisco cookie crumbler

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    i'm struggling not to turn the a/c on at 89 degrees. and the humididity is a killer.