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2010 Prius | bought IInd Hand | Was getting 50 for 3-4 month | Now only 42 | Plz Guide

Discussion in 'Gen 3 Prius Fuel Economy' started by rajul.urvashi, May 1, 2015.

  1. rajul.urvashi

    rajul.urvashi Junior Member

    Joined:
    May 1, 2015
    3
    0
    0
    Location:
    Reston
    Vehicle:
    2010 Prius
    Model:
    IV
    - What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual calculations)

    Ans. I am getting 42 Mpg. Trip Computer.

    - What fuel economy are you expecting and why?

    Ans. Similar Situation friend of mine getting 53 Mpg. I bought it second hand. When I bought in 2014 Aug it was giving 49-50 Mpg. After 3 month it dropped to 43 Mpg. Then winter started and it went to 39 Mpg. Now Summer 2015 started it came back to 42.

    - What are the approximate outside air temps?

    Ans. 65F to 75F in summer

    - How long are your trips?

    Ans. My office trips are just 2 miles. But I have many type of trip. Like 15 miles trip, 40 miles trip. 250 miles trip. In all big trip I am checking my mpg.

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

    Ans. I don’t know. But I don’t think so any problem with my as it 2010 3rd generation. Previous own was lady. Even on computer it show best mileage achived is 58 mpg.

    Have you had your alignment checked? Any pulling or abnormal tire wear?

    Ans. Ever since I bought it. I sent it twice for regular service at dealer as there was MPG dropped. I got their all recommendations(hefty and ripping) done. But no improvement. Now I DON’T FEEL LIKE GOING TO ANY DEALER AS I FEAR THEY WOULD AGAIN RIPP ME. Fuel System Cleaning and blah blah. I myself tried to clean throttle cleaning following up you tuber. Without opening any major parts. YET I could not figure out how to MAF sensor cleaning. Finding Video of the same.

    - 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?

    Ans. City 40-50
    Ans. Highway 60-75 sometimes 80

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

    - What are your tire pressures?
    Ans. 45


    - Is your oil overfilled? (i.e. above the full mark on the dipstick)

    Ans. Since it had been to authorized dealer for twice I am sure this has been taken care. Even synthetic oil has been changed.



    - Make, model, year, engine and transmission of previous car? What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.)

    I don’t know why you are asking previous car but this car is Prius IV 2010. I had not any car before this.

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

    Ans. NY NJ AND VA

    - How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking?

    Ans. I drive as per point and glide. I have seen 10 minute u tube video. I follow is religiously.

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

    Ans. I use Eco mode .

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

    Ans. NO don’t Idle up.

    - Are you driving using D or B mode?

    Ans. D mode

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

    Ans. AUTO- 72

    - Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g.GoodyearAssurance).

    Ans. Goodyear

    - If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute?

    Ans. Nothing specific. But few observation. I notice visible smoke from silencer but not that great smoky. There is a 0 to 100 Mpg indicator that help you to get best mileage. I NOTICED THAT Even though while driving I release accelerator fully then to indicator remain on 20-25 for few second and then it start gradually increasing to 35-40 and 45.

    MY CONCERN:

    I really don’t know how would I solve my problem. I am in Reston, VA. If any good HONEST prius mechanic forum can recommend. Please Guide.
     
    #1 rajul.urvashi, May 1, 2015
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,049
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    welcome! your 12 volt may have gone south. it's rasy to check and eliminate as a problem. 5 years is an older battery. you're taking too many things for granted. learn how to check your oil, it's important, and you can't trust that the dealer did it right, or that it hasn't gone down since then.

    smoke from the silencer is not normal, check the oil level. all the best!(y)
     
    #2 bisco, May 1, 2015
    Last edited: May 1, 2015
  3. bwilson4web

    bwilson4web BMW i3 and Model 3

    Joined:
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    Location:
    Huntsville AL
    Vehicle:
    2018 Tesla Model 3
    Model:
    Prime Plus

    The car takes ~1.5 miles just to warm-up. This is the range where a plug-in makes more sense.
    Dealers and many car repair places are notorious for selling more oil, overfilling the engine. I do my own oil changes because I only put in quality oil, filter, and the right amount. If you don't look, you don't know.

    Bob Wilson
     
    #3 bwilson4web, May 2, 2015
    Keithstef likes this.
  4. mikee1680

    mikee1680 Junior Member

    Joined:
    Nov 16, 2012
    5
    0
    0
    Location:
    Los Angeles, California
    Vehicle:
    2010 Prius
    Model:
    IV
    Same issue with mine.


    iPad ?
     
    #4 mikee1680, May 2, 2015
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,049
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    sorry, but at least you know what to do now.;)
     
    #5 bisco, May 2, 2015
  6. walter Lee

    walter Lee Hypermiling Padawan

    Joined:
    Oct 26, 2009
    1,126
    376
    5
    Location:
    Maryland
    Vehicle:
    2010 Prius
    Model:
    III
    further questions
    ================
    1) on your trip computer what is the average speed (mph) and average fuel consumption (mpg)
    2) what is your daily commuting commute distance(miles) and time (minutes)
    3) what is the brand-model of the Goodyear tires you are using on the Prius?
    (are they all season radials or snow tires?)
    4) Do you have a rooftop rack, bicycle rack, or any attached externally to your Prius?
    5) what is your top super highway speed and how long do you drive (distance that you travel) when going at this top speed?
    6) Are you carrying any cargo (regular-commuting passenger+cargo weight)


    preliminary review
    ================

    I agree with bob - if your daily commute is 2 miles then you should be driving a Prius Plug in and recharging every night. If your 2 mile commute is something of sure thing for the next 4 years - I think you should trade your regular hybrid for a PiP.

    Bob warning about oil levels is also reasonable, too.

    The 12 volt battery on my 2010 Prius is doing fine so far...

    My educated guess is that your high top speed when you are driving on the super highway is limiting your fuel efficiency. To get closer to 58 mpg like the previous owner you need to give yourself more time to get somewhere and keep your Prius top speed closer to 60 mph when on the super highway. The only way I know of to get 58 MPG at speeds over 65 MPH is to draft(slipstream) behind a big bus or truck. At above 65 mph - even driving without brakes (gravity assisted accelerations) will not likely get you much better than 50 MPG - the aerodynamic drag load is way too high at that speed (on a relatively flat road ) and unless someone else is doing the heavy lifting for the Prius or you have a tail wind of +15 mph - its fuel efficiency drops. BTW: The most fuel efficient speed for a regular Prius hatchback in all electric mode is around 15 mph.
     
    #6 walter Lee, May 9, 2015
    Last edited: May 9, 2015
  7. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    590
    294
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    I've learned a few things over the last few weeks with my 2010 48K miles. I never did anything other than put gas in and changing the oil.
    After reading a few posts on an automotive board on fuel system cleaners I decided that maybe I should think about running a bottle through the Prius. I poured in a bottle of Techron and within two hundred miles I saw a jump in my city mileage by about five to ten percent. After seeing this it got my attention and I also started filling with a Top Tier gas, Shell. Before this I filled up at what ever gas station was the cheapest, usually the Sunoco down the street. So far so good, the increased fuel mileage has been continuing on with the second tank.

    You have no idea what the past owner was filling your car up with, bottom of the barrel weasel pee quality or something of more of the Top Tier lineage. If you have over 30K miles on the car I would run a good fuel system cleaner through the gas tank and see if it has any effect on your mileage. While your at it switch over to a high quality gas like Chevron or Shell and see if it also helps on your mileage. I've read a few threads on people that have played around with different brands of gas and it seems to help out some with slightly better fuel mileage.

    You may want to Google Top Tier gas to see what stations are near you.

    I can only recommend two fuel system cleaners.

    BG 44K which seems to the best you can get. It is available at various car dealers parts departments.
    The other is Techron which is available at most auto parts stores.
     
    #7 ALS, May 12, 2015
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