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2015 Prius gas mileage way worse than my old 2008

Discussion in 'Gen 3 Prius Fuel Economy' started by scotttyb68, Feb 5, 2016.

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  1. scotttyb68

    scotttyb68 Junior Member

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    I traded my dear old 2008 Prius for a 2015 in October 2015. It's winter here in Michigan, mild by our standards but still cold. My '08 would get 46-48 MPG in summer and 42-44 in winter usually. I got the '08 new BTW, this 2015 is getting under 40 MPG the last 3 tanks. I traded in part for new warranty and the supposed 50 MPG. I am regretting giving up the old girl. My area is pretty flat and has a nice mix of slower city speeds and highway speeds. The new car has 2800 miles now. Not a lot because I am hating even looking at it no less going for a drive. Any thoughts, similar trouble? Solutions? Thanks.
     
  2. mrstop

    mrstop PWR Mode

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    While I didn't have a Gen II as a point of comparison, I think overall you should be getting better mileage over time. Obviously the cold is probably not helping. Do you have 15" or 17" wheels and tires? Sometimes the tires need to be "broken in" so that could effect things. Also, your trips and the weather may not be apples to apples. Also, we don't always remember what we think we do. I would give it some time and see the long term trend. Input your information into fuelly or log it elsewhere so you can see your real trend overtime.

    My lifetime average is about right at 48 MPG and that is driving hilly terrain and short trips to pickup kids in the cold. I also drive the car without too much conscious effort on hyper-miling. While we're a little warmer in Ohio, we're subject to similar weather.
     
  3. scotttyb68

    scotttyb68 Junior Member

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    Thanks, I have 15 inch tires which are Goodyear just like the old one. I live near Lansing so yes our temps would be very similar. Having the Gen 2 so long I know her traits like the back of my hand, maybe you are right, might not be apple to apple. I know the 3 is bigger and the ICE is larger than the '08. I will keep a log, that's a great idea. I always trusted the cars estimate, I figured the computer should know. It's been such a mild winter I would expect at least 43 MPG.
     
  4. Caniac

    Caniac Active Member

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    I notice the same thing. I traded my '07 in on a '15 about 6 weeks ago. My mpg always fell way off in winter so I'm going to wait until it warms up to start worrying. I'm on my 3rd tank now averaging 39.4 which is slightly higher than my gen 2 was getting but still a lot less than I'd like. It probably isn't helping that all my trips are usually <5 miles.

    I miss my gen 2 also.
     
  5. sillylilwabbit

    sillylilwabbit Active Member

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    Your cars are still new, they have to break in a little longer.

    I also noticed, the shorter your trip, the crappier your gas milage.




    iPhone ?
     
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  6. mrstop

    mrstop PWR Mode

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    You can click on my Fuelly image in my signature. If you scroll down to recent fill-ups and the click all you can see the variation I experience. In the last few fill-ups, I have been driving a lot 2-5 mile trips lately (more so than usual) and you can see how my mileage has suffered as a result (even compared to previous years).
     
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  7. Former Member 68813

    Former Member 68813 Senior Member

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    that will do it. gen 3 with 1.8 engine is probably worse in that regard than gen 2 with 1.5 and it's thermos bottle.
     
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  8. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I found the first 1.5-2.0 miles to be sensitive in cold weather. So let me suggest a practical experiment IF you can get a time-lapse video app or your cell phone has enough video memory to record a cold-start, full commute. Rig up a holder for the camera so you can make a video recording of a trip meter:
    1. start the video recording of the trip meter
    2. READY car
    3. Reset the trip meter
    4. Drive normal route
    Replay the video with a spread sheet and enter:
    • miles and MPG (at least 1 mile granularity but more is better)
    • calculate the fuel burned over each mile or distance section
    What I found in Huntsville, AL, is the first 1.5-2.0 miles, typically 30-35 MPG. But once past that initial warm-up, the car MPG shoots up to 60+ MPH (typical local speeds 45-55 mph.) Earlier tests with the 2003 Prius shows below 55 F, the MPG curve follows the temperature defined, air density, at highway speeds.

    Some key engine coolant temperature points:
    • <40C - engine must run all the time
    • >40C to 55C - engine will shutoff at a stop IF the heater is off
    • >55C - normal engine shutoff even with heater on
    There are comments in the 2016 New Car Features suggesting that if the traction battery is too cool, <0C, the engine has to run more. This suggests one approach might be to get a JC Whitney (or equivalent) battery warmer for those who live in cold climates. But Huntsville is too mild to justify even the test. Another approach might rig up a small hair dryer and duct to pre-heat the traction battery but this is a very advanced technique.

    GOOD LUCK!
    Bob Wilson
     
    #8 bwilson4web, Feb 6, 2016
    Last edited: Feb 6, 2016
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  9. bisco

    bisco cookie crumbler

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    o/p, if everything else is the same, then there is something wrong with your car. you should be getting better mileage in a gen 3, not worse. try to consider all the outside parameters first. if you can't think of anything that has changed, start looking at your car. tyres, 12v, oil level and etc.
     
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  10. JimN

    JimN Let the games begin!

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    Is the tire pressure the same on both cars? Is the 2015 dragging a brake? Has the grill blocking changed? Is the new one in ECO?

    If you can't get at least the same fuel economy as the 2008 under the same conditions something is wrong. It took me quite some time to unlearn how to drive my 2006. Patience.
     
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  11. calirider

    calirider ECOmobile

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    A Plug-in Prius would be ideal for this.
     
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  12. bisco

    bisco cookie crumbler

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    oh heck yeah.
     
  13. retired4999

    retired4999 Prius driver since 2005

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    Yes it would be Ideal!
     
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  14. PosauneGuy

    PosauneGuy Member

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    Check tire pressure. I bought a 2015 Prius a couple of months ago (was driving 2011 Prius). Right off the lot, I had a lot of trouble getting above 40 mpg. Then I checked the tire pressure and tires were around 34/32 psi. Bumped them up to 40/38 psi and mileage increased substantially. When temps are hovering in the 30s, I'm getting 44-46 mpg (which is what the 2011 Prius is getting) and in the single digits I'm in the 38-42 range. Currently on third tank of gas and the mpg is matching the 2011 Prius.
     
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  15. Former Member 68813

    Former Member 68813 Senior Member

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    not always, read above.
     
  16. bisco

    bisco cookie crumbler

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    if you're suggesting short trips are less efficient in the gen 3 than the 2, i suppose it's possible, but we would need some evidence.
     
  17. anthdc

    anthdc Junior Member

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    [​IMG]

    Same here man. Driver in San Francisco. ^ Are these numbers going to get better?
     
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  18. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Welcome to PriusChat.
    It is possible. Start with: Fuel economy complaints/queries? Please copy, paste &amp; answer these questions, esp. if you&#039;re new | PriusChat

    The questionaire helps identify the 'low hanging fruit.' Then we can approach your specifics.

    For grins, introductions are in order. I'm a 66 year old engineer who has found the Prius to be a fascinating hobby. Yesterday, I drove our 2003 Prius, Gen-1, to work and this morning, our 2010, Gen-3. So let me suggest a quick test:
    • Push the "start" button but without pressing the brake to turn the car on.
    • Reset one of the two trip meters, A or B.
    • Hold the brake and push "start" to get the car READY to drive.
    • When you've driven over a mile, safely(*) take a quick snapshot of the trip meter.
    • Then reset the trip meter and continue.
    • At end of drive, take a second snapshot of the trip meter.
    If you'll post these two snapshots, we'll be able to show a fundamental aspect of Prius driving and how to exploit the car. <GRINS>

    Bob Wilson

    * - safely means just that. If it is difficult, we can achieve the same thing by resetting both trip meters. Then after driving a mile, reset one. When the trip is done, take a photos of both and post. We'll go over what the two trip meters are telling us. This approach means both photos can be taken when parked at the destination.
     
  19. trip1027

    trip1027 Member

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    Oo can we do for me too lol

    SM-N920V ?
     
  20. bisco

    bisco cookie crumbler

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    of course, just post your snapshots.;)