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

Only 500 miles, but good mileage so far

Discussion in 'Prius c Fuel Economy' started by Gasoholic, Feb 17, 2017.

  1. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    I bought the 2016 Prius C3 a couple of weeks ago. 500 miles of driving. So far, I have driven it up a mountain canyon, 4,000' rise, twice, about a 90 mile round trip each, 60mpg average for a round trip. The rest of the driving has been in town. Overall mileage is shown at about 52mpg on trip B which I have not reset. I see better mileage in town at times, 54-62mpg on short trips. So mileage seems to be very close to what the EPA estimates are on the sticker. I am pleased with the mileage, seems to fit my needs.
    Gasoholic
     
    65mpg_utahn, bisco and skayaks like this.
  2. JaredSJLY

    JaredSJLY Junior Member

    Joined:
    Jan 6, 2017
    28
    4
    0
    Location:
    US
    Vehicle:
    2013 Prius c
    Model:
    Three
    Thats great! Youre gonna love this car, i find new reasons to love it every day!

    Posted via the PriusChat mobile app.
     
  3. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    First all highway trip of 130 miles each way, @ 65 mph, 58 mpg, not too bad! That was my wife driving and no cruise control. I think I could have done a little better. :^)
    Gasoholic
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    congrats and welcome! thats excellent work, all the best.(y)
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    If you're inclined: start tracking mpg: record your fillups and distance travelled, keep a log. (y)
     
  6. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    I have set my Trip B, from the day it was driven off the lot. This gives me an overall look at mileage, but I use the Trip A to gather information on the individual trip.
    So far, I have found that the car can deliver much better mileage than the EPA tests indicate. I figured this to be true, EPA testing has gotten a bit off track from actual use in my opinion.
    The Prius C3 is a nice compact car, great for in town and not bad at all on the highway too.
    Gasoholic
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Toyota fudges the numbers, 5~10% positive bias. It's at least semi consistent bias, but something to keep in mind. Also, whenever you disconnect the battery, the trip data is gone. Really depends how much you care, if you're seriously into tracking tank by tank, or just want a bit of feedback.
     
  8. Sean Nelson

    Sean Nelson Active Member

    Joined:
    Dec 30, 2014
    421
    182
    0
    Location:
    Vancouver, BC Canada
    Vehicle:
    2012 Prius c
    Yeah - I calculate my fuel economy at every fill-up based on actual litres pumped, and I also compare it to the reported "Trip B" fuel economy, which I reset at each fill-up. The figure reported by "Trip B" is always about 5 to 7% optimistic - i.e., it reports slightly better fuel economy than I actually get as measured by litres pumped. And I seen this reported by a lot of people, so it seems to be pretty consistent across the fleet.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    After a few accidental resets of trip meters, I opted to recording odometer reading at each fill up, then do the math: subtract previous from current odo reading, to get distance travelled. With a spreadsheet it's very easy, and fuelly can be setup that way as well. I still reset trip meters, for feedback and as a cross-check.

    Our previous Honda Civic Hybrid had a fuel economy display that was either spot-on, or slightly pessimistic. It can be done. It's a bit embarrassing, that the auto maker leading the mpg pack insists on exaggeration.
     
  10. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    I am sure that you are right, I will check after the next fill up, do the math and see. I know the trip B was showing 52 mpg last time I looked I believe, so maybe it will actually be less than that.
    My Dodge Cargo Van, shows exact mileage, verified by fill and compute. It is fairly easy to make the trip meter accurate, the fuel injectors can be monitored for flow rate and the computer can compute the burn. Not sure why the Prius C would not be pretty close, but I will see how much it differs.
    Gasoholic
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    The only plausible answer, sadly, seems to be: by design. The errors are quite consistant.
     
  12. davids45

    davids45 Active Member

    Joined:
    Nov 23, 2016
    104
    131
    0
    Location:
    Chatswood, NSW
    Vehicle:
    2016 Prius c
    Model:
    One
    G'day,

    Checking my speedo against a necessarily accurate GPS system's indicated velocity, my c is 4-5% fast. Better than my wife's Yaris at 9% fast, but not as good as my traded-in Echo at 0-1%. These variances were also consistent with the do-it-yourself roadside speed indicator signs - 6 signs spaced 1km apart along the road so you could check your speed/odometer.

    Does everyone correct for their likely odometer error when measuring fuel consumptions? Or at least, mention when they do do such a correction? Otherwise, car-to-car fuel use comparisons are questionable, at the decimal place values at least.

    Presumably the Prius uses its own distance measurement (reported to us as ODO/TripA/TripB), so doing a manual calculation based on your fuel from the pump per your odometer reading should match the car's internal calculation - any difference being in the fuel volume value used in the calculation.

    Thus far (I've had the c for 3 months), I see a fairly consistent over estimate of about 5% by the car compared to my L/100km value, using the same ODO readings. Litres in topping up for the distance since last topping up. I believe our local government reliably checks the accuracy of service station pumps so the fuel volume estimate by the car itself seems more suspicious of being 'optimistic' (reading less than it should).

    So, there is a variance in the the fuel volume and in the distance travelled for that volume, both tending to exaggerate the efficiency of a vehicle getting from A to B. The distance, A to B, is presently like Caesar's wife ;) .

    David S.
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    There is no connection between speedometer and odometer accuracy. The first typically reads high, by legislation, to slow people down. The second has to be reasonably accurate, or lawyers get interested.

    And mpg accuracy? Now who would want to fudge that...
     
  14. Sean Nelson

    Sean Nelson Active Member

    Joined:
    Dec 30, 2014
    421
    182
    0
    Location:
    Vancouver, BC Canada
    Vehicle:
    2012 Prius c
    My speedometer seems to be very accurate, but measured manually and against my GPS. I never see more than about a 1km/h difference, and I attribute that to rounding error.

    But I don't think I've actually checked the odometer. I'll have to do that one day.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    My speedometer seems invariably higher compared to my Garmin GPS, around 2%. I'm ok with that, abide by what the speedo says. The odometer is going to be reasonably accurate though, at least with stock tires. If it's reading high, for example: lawyers will be going after the manufacturers, with claims that cars are running out of warranty prematurely.
     
  16. 65mpg_utahn

    65mpg_utahn New Member

    Joined:
    Feb 27, 2017
    6
    2
    0
    Location:
    St. George, UT
    Vehicle:
    2014 Prius c
    Model:
    Four
    I purchased this little gem on Saturday and I can't even believe how quiet it is. I had no idea that you could enjoy something you can't even hear and still gets me 55mpg on the Freeway & 65 in town. Don't know if its the 91 Prem. octane I'm putting in it. Either way I'm excited to have became a Jedi Prius Driver!!!
     
    Polish Prius likes this.
  17. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    I burn regular gas, maybe I should try premium, any thoughts on that. I have a 2016 Prius C3 with a few hundred miles on it.
    Gasoholic
     
  18. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Premium is higher octane, it's sole purpose being to prevent pre-ignition in high compression engines. It's a small percentage, the cars on the road that actually need the stuff. But you wouldn't think that, looking at the pump arrangements in gas stations. Anyway: it'd be spec'd in the Owner's Manual if needed. Waste of money.
     
    65mpg_utahn likes this.
  19. davids45

    davids45 Active Member

    Joined:
    Nov 23, 2016
    104
    131
    0
    Location:
    Chatswood, NSW
    Vehicle:
    2016 Prius c
    Model:
    One
    G'day,

    Here in NSW, we have the option of E10 - up to 10%vol ethanol in regular unleaded.
    Regular here has a RON of 91 (Research Octane Number - 'octane' (2,2,4-trimethylpentane) is RON 100 for the rating test purposes) but E10 goes up to RON 94 with the alcohol addition. Alcohol has a high RON, in other words.

    However, E10's 'power' (combustion energy or calorific value) is decreased since there is more energy in burning the pure hydrocarbon 'regular' compared to burning the alcohol mix (ethanol has a lower calorific value). If burnt with full or equal efficiency, of course.

    In theory, with its lower calorific value, 94RON E10 should give slightly less milage than 91RON regular, but it's more how and where and when the car is driven, than the fuel itself, that determines mpg or L/100km. I see no difference between regular and E10 for my driving experience.

    Our "Premiums" in Oz have 95 or more RON and, as Mendel Leisk rightly said, are only needed in high compression engines where power, not efficiency, is the target. European cars seem to think this high compression is a good idea with their tendency for turbo-boosted small-capacity engines. Hence their need for high RON fuels.

    The designed minimum RON for the Toyota engine's fuel is 87, merely to stop pre-ignition ('knocking' or 'pinging' where the fuel-air mixture ignites prematurely due to the compression in the cylinder before the spark plug sparks at the intended part of the stroke).
    Japanese cars (engines) seem to take a more practical, world-friendly view where across the world, fuels may be "variable" so the lower RON the car can use, the better.

    When it's available, I use E10 in my c. E10 is taxed a little less here than Regular (about 3 cents per Litre less).
    But by choice, I would never use our over-priced 'Premiums' (these can be more than 15 cents per Litre dearer!). These 'Premiums' (definitely a marketing term, not a technical term, in my opinion) have pretty much the same power (combustion energy) as the other fuels on sale, and are wasted in a well-designed low-RON ICE such as the Prius's.

    Then again, it's hard to argue against the 'placebo effect' :) . If you think it'd do you or your car good, 'go for it' ;) . It's only money after all :D .

    Keep smiling,

    David S.
     
    Mendel Leisk likes this.
  20. Gasoholic

    Gasoholic Junior Member

    Joined:
    Feb 17, 2017
    35
    12
    0
    Location:
    Bakersfield, Ca
    Vehicle:
    2016 Prius c
    Model:
    Three
    Ok, so after 366 miles, I filled the tank and compared the reading from Trip 1 and the actual mileage. Trip 1 showed 55.1mpg, the fill up and math show 57.1 mpg, so I think that they are pretty close, with the possibility that the fill up was not exactly to the same point as before.
    Blueman
     
    65mpg_utahn likes this.