1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Terrible MPG: What am I doing wrong?

Discussion in 'Gen 4 Prius Fuel Economy' started by CEnsalata, Nov 26, 2016.

  1. CEnsalata

    CEnsalata New Member

    Joined:
    Nov 5, 2016
    15
    14
    0
    Location:
    Vermont, USA
    Vehicle:
    2016 Prius
    Model:
    Four
    brand new 2016 Prius Four driver here. Only had the car since Monday. My trips are around town, frequent stopping. Trips range on average from 8-15 min. It's been cold; in the 30s & 40s Fahrenheit. I've been using my seat heat and also the interior heat. The car was delivered to me from out of state with around ~250 miles on it and an average MPG in the 40s. I've put on an additional 50-60 miles since then and the MPG is like 37. Am I doing something wrong, or is this the best I can expect given my driving conditions?

    Thanks.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    maybe not the best, but the short trips might be the majority of your problem. have you considered a block heater?

    of course, tyres pressure is important, and keep it in eco if mpg's are more important to you than full blasting heat. check the oil level, although that's not a likely suspect in a new car.
     
    RCO likes this.
  3. aurelio

    aurelio Member

    Joined:
    Feb 15, 2012
    72
    56
    0
    Location:
    Mexico
    Vehicle:
    2016 Prius
    Model:
    N/A
    Cold weather, short trips and interior heat... it will keep the engine running ruining your mpg. Specifically short trips. But compared to any other car you are doing great anyway, at least 60% less than a small car.

    You can expect usually 50 to 60 mpg with better weather conditions. I have reached 80mpg in Mexico city with heavy traffic.

    Give it a try with a longer trip, you'll be surprised.

    SM-T813 ?
     
    mertechperformance, RCO and Merkey like this.
  4. mrdata71

    mrdata71 Member

    Joined:
    Oct 19, 2016
    37
    50
    0
    Location:
    US
    Vehicle:
    2020 Prius Prime
    Model:
    Limited
    I can also notice the MPGs are better when it is warmer outside. I am in Houston, TX, but it does run more when its cold outside. ECO Mode and always run your A/C on auto. set that temp to 75 and it loves that. Make sure you reset your gauges after a fill up to see how you are driving. And do not be a lead foot. That will ruin your MPG as well. I AVG at least 50MPG per tank. my best before a fill up was 64MPG.

    Posted via the PriusChat mobile app.
     
    RCO likes this.
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Several things you can do:

    1. Get the block heater (already suggested by @bisco). This is a biggie. We got it at time of purchase (for an exorbitant $400 :oops:) and use it pretty much religiously, year 'round. I'd suggest to plug-in 2 hours before you need to go, most effective. In the depths of winter a bit more, maybe. Installed price is around $200~250 through dealership?

    It does not fully warm the car, only raises the coolant temp by around 20~30C, maybe 40~50F. But this really gives the car a "leg up" in the warm-up process.

    2. Lower the cabin temperature some, dress warmer, and avoid (or at least reduce) seat warmer use. The car is monitoring what you have cabin temp set at, and changing how soon it allows engine shut-off accordingly. If you have the heat up high, perhaps vent mode set to heat/defog, it sees this, and delays engine shut down, in order to warm the engine more. It's seeing your priorities, adjusting accordingly.

    3. Are you parked in a garage, or out in the open? If the car's sheltered there's a lot les need to run it at idle, clearing the windshield.

    4. Short trips are always a killer. Avoid unnecessary jaunts, consider walking if practical. And consolidate trips if possible: save up chores and combine into one trip?
     
    RCO likes this.
  6. bhtooefr

    bhtooefr Senior Member

    Joined:
    Apr 4, 2016
    1,396
    1,489
    0
    Location:
    Newark, OH, USA
    Vehicle:
    2016 Prius
    Model:
    Three
    Houston? That's not cold, and 75 is not how to get good mileage in an area where it actually gets cold. I suspect the engine would simply never shut off, at this time of year, in Ohio, on my similarly short trips. The OP's in Vermont.

    I've been setting the HVAC to 60, myself, in colder weather. Also, seat heaters are more efficient than cabin heat, so you're better off using them to warm yourself than using more HVAC. (I don't have them, myself.)

    Another thing worth doing is to carefully use the throttle to burn off the battery power at the end of your trip - the depleted battery will be recharged by the engine warming up anyway.
     
    RCO likes this.
  7. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Also - fill your tank, zero one of your TRIPs (I think most are using TRIP A for individual tank recording) and drive it till it's at least ½ empty. Then fill it and calculate the MPG. For some reason, (and not just with PRIUS, my previous FORD did the same) the dash MPG readout never works right till you've done a fill.

    The dashboard readout is a little optimistic.
     
    RCO and krmcg like this.
  8. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    12,470
    6,862
    2
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    1) I would not have recommended a hybrid to you, as your trip distance is too short for the engine to ever warm up. Your trips seem much more Electric car or Plug in Hybrid friendly, as short trips can be all electric. considering a Prius | PriusChat The best I can advise now is to combine trips where possible and when you do, drive the longest leg first.

    2) You have no idea how much gas the dealer put in, so there is no accurate way to measure MPG on your first tank. Learn the controls, adjust the mirrors, try out the seating positions, and get comfortable. Once you start filling the tank to the same level each tank, (always stop at the second click, as an example) you can get accurate results and can obsess over MPG. (You can track it online at Fuelly.com)

    3) Weather, especially cold weather will hurt MPG. I do not get much cold weather, but even in MS I can tell summer from winter. Vermont may well reward a Engine Block heater. Engine Block Heater for 2010-2015 Toyota Prius - PriusChat Shop

    4) Your use of the car will effect your mileage. (I use mine as a cargo van, and it shows) As a group, Rural Mail Delivery drivers get the worst mileage, they are constantly speeding up from a stop and slowing to a stop, never cruising. (But the Prius is WAY better than what they drove before, just horrible compared to most owners)
     
    Montgomery, RCO, Merkey and 1 other person like this.
  9. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    I haven't found that short trips give particularly bad fuel economy. Some of my best litres/100km have been on a mix of short trips. Even if it starts the engine when you start off, it'll go back to EV Mode from time to time - hybrid style - whether it's short trips or long trips. Round-town type driving gives me better economy than highway driving.
     
    RCO likes this.
  10. Prodigyplace

    Prodigyplace Senior Member

    Joined:
    Nov 1, 2016
    11,696
    11,317
    0
    Location:
    Central Virginia
    Vehicle:
    2017 Prius
    Model:
    Two
    I find short trips are worse for me but I am located in the foothills of the Blue Ridge mountains. I work in a city that is called "The city of seven hills". Definitely not hybrid friendly territory.
     
    RCO and alanclarkeau like this.
  11. CEnsalata

    CEnsalata New Member

    Joined:
    Nov 5, 2016
    15
    14
    0
    Location:
    Vermont, USA
    Vehicle:
    2016 Prius
    Model:
    Four
    My car gets parked in a carport where there is no electricity and no possibility of electricity, so that excludes electric vehicles and plug-in engine block heaters. Which is really a shame, because I pay for my electricity through a solar farm coop and would have loved to get an all-electric vehicle.

    I did make the dealer top the tank off on delivery and I attempted to reset the odometer, but I must've messed up because both Trips A & B still show the full 300+ miles, not my 50-60 miles. However, I can reconstruct from the daily log my average mileage and gas mileage. From those logs it looks like my average gas mileage is between 39-42mpg. The car's overall mpg average has crept to 40.2.

    In a separate post yesterday I was asking about "B" mode for braking; I had been using that a lot. It seems as though not using it is actually better for mileage, Also, it's supposedly unnecessarily in all but the steepest of hilly drives.

    Even if I'm not maximizing the Prius mpg yet (and hopefully I will be soon, or at least seasonally) I'm still getting 10+ mpg better than I was in my VW Jetta Sportwagen TDI.
     
    RCO likes this.
  12. bhtooefr

    bhtooefr Senior Member

    Joined:
    Apr 4, 2016
    1,396
    1,489
    0
    Location:
    Newark, OH, USA
    Vehicle:
    2016 Prius
    Model:
    Three
    That's the big thing, even if a Prius is doing badly in short trips, it's probably doing far, far better than whatever you had before - my TDI would've gotten about 35 tank average in current Ohio conditions with my short tripping (and my Miata low 20s), and I'm still breaking 50 so far in the Prius. (Conversely, in warmer (but not hot) weather, I can get fantastic mileage.) No access to electricity is why I have one as well, instead of a PHEV.

    As far as resetting the trip odometers, press the trip button and immediately release, repeat until the thing you want to reset is showing. Then, HOLD the trip button until it resets.
     
    Merkey and RCO like this.
  13. HamiltonPrius

    HamiltonPrius Member

    Joined:
    May 17, 2016
    107
    64
    0
    Location:
    Parts unknown (in the USA)
    Vehicle:
    2016 Prius
    Model:
    Two
    With all due respect, learn how to drive the car. No jack rabbit starts, no speeding, stay out of the red power level on your dash read out as much as possible.

    I do a lot of short trips and am averaging 80 mpg. Colder conditions will effect mpg but not 40 mpg.
     
    #13 HamiltonPrius, Nov 27, 2016
    Last edited: Nov 27, 2016
    alanclarkeau and RCO like this.
  14. bhtooefr

    bhtooefr Senior Member

    Joined:
    Apr 4, 2016
    1,396
    1,489
    0
    Location:
    Newark, OH, USA
    Vehicle:
    2016 Prius
    Model:
    Three
    Eh, that really depends on how short the trips are, and what your road conditions are.

    If the engine never shuts off, you'll probably get in the ballpark of 40. I certainly have days where it takes 2-3 miles to shut off, and it's not even winter yet in Ohio.
     
    N.J.PRIUS, Merkey, RCO and 1 other person like this.
  15. AKCoffee

    AKCoffee Junior Member

    Joined:
    Jan 14, 2016
    46
    23
    0
    Location:
    Minnesota
    Vehicle:
    2014 Prius v wagon
    Model:
    Two
    Grill Block

    Stuff the lower grill with pipe insulation in moderately cold temps: sub 45f. Block one of the upper grills when temps dip below 30f (highs). You can be more aggressive than that if you monitor coolant temp with a scan gauge...ultraguage...torque app...
     
  16. Prodigyplace

    Prodigyplace Senior Member

    Joined:
    Nov 1, 2016
    11,696
    11,317
    0
    Location:
    Central Virginia
    Vehicle:
    2017 Prius
    Model:
    Two
    Do NOT block the grill. The 4th Gen has active grill shutters
     
  17. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring

    Yeah, that's one thing 3rd generation owners responding will miss: the 4th gen seems much more willing to leave the engine off if ambient temps are mild and state-of-charge is available. Third gen: 10~15 seconds in, the engine fires up.

    OTOH, original poster is in Vermont, so I guess colder ambient temps are requiring engine start up a lot more, this time of year.

    I hope Toyota knows what they're doing: compared to 3rd gen, the new Prius is very willing to use the battery-only, particularly right after start-up. Hopefully don't overtax it.
     
    alanclarkeau likes this.
  18. Prodigyplace

    Prodigyplace Senior Member

    Joined:
    Nov 1, 2016
    11,696
    11,317
    0
    Location:
    Central Virginia
    Vehicle:
    2017 Prius
    Model:
    Two
    When I first got my 4th Gen, the engine did not usually start up. I expect it to start when cold, but a few times lately, I thought it was warm enough, but the engine started anyway.
     
    Mendel Leisk likes this.
  19. raspy

    raspy Senior Member

    Joined:
    Jul 6, 2016
    438
    699
    0
    Location:
    London, UK
    Vehicle:
    2016 Prius
    Model:
    N/A
    The figures cited by the OP are normal. Today I drove around 6 miles to the supermarket, in Eco mode, with the AC on, after the car had been parked up overnight. The engine came on immediately and stayed on a LOT during those 6 miles, despite having a reasonably full battery. My MPG figures from that journey seem low, just like yours (remember, you would have to reduce the MPG in my photo by 20% to compare with US figures)

    Then I went for lunch, so the car was parked for 90 minutes outside, drove back home, except this time, a few points in my journey required pedal to the floor acceleration, and despite this, my MPG was way better than from a cold start where I was super light on the gas pedal.

    The numbers from cold start journey are on top, the return journey after lunch are on bottom.
     

    Attached Files:

    RCO likes this.
  20. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    5,596
    3,770
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    Most of these threads start with very little info by the driver. That you state right up front most things that negatively affect economy tells me you already know the answers but want some confirmation. 37mpg isn't that bad. It will bounce back quite nicely in the spring/summer when the temps are better and the car is broken in. Your yearly average is what's important.

    Too bad as that was what I was going to suggest. A plug-in would work very well for you and your circumstances.

    Where are you?
     
    RCO likes this.