Fuel range

Discussion in 'Gen 3 Prius Fuel Economy' started by Triparadox, May 15, 2019.

  1. Triparadox

    Triparadox Junior Member

    Joined:
    Mar 12, 2019
    46
    10
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Three
    So if we do a very simple math:
    They claim this vehicle can do 48 mpg at highway and 52 mpg at city. Let's just make it 48 all the way. The capacity is 11.9 gal. If we multiply 48 with the gas tank, it will give us 571 miles. However, when I top off the gas tank, it gave me about 330 or 340 miles only. Isn't something off??? My mpg consumption is at 47, so it shouldn't be that far. Also AFAIK, the gas range will not be calculated according to our mpg, but from the manufacturer.
     
  2. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    812
    528
    0
    Location:
    Indian River County, Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    It's says 11.9 gallons, total. But the usable is less. You could run until you run out of fuel.
    Then fill up and you'll get close to the 12 gallons. But that would be foolish.
    I was heading to the station when the last marker started flashing of the fuel gauge.
    It took 9 gallons to fill. I believe the most I'll filled with is 10 gallons.

    And this if pretty much the same with any car.

    If you drive 55-60mph, you'll mileage will go up. :)
    I got 52mpg yesterday driving about 300 miles on average of 60mph.
     
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    78,122
    33,002
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it should be figuring around 450 based on your consumption, and what toyota considers the usable portion of the tank. (the rest they consider 'safety'.

    but it is based on past driving history, not just your 47 currently. how long have you owned her?
     
  4. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    1,816
    1,660
    1
    Location:
    BOY
    Vehicle:
    2012 Prius
    Model:
    Four
    That’s for the Prius C.
     
  5. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

    Joined:
    Oct 17, 2010
    32,776
    21,766
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    How much gas are you needing to add, roughly? I'm betting a lot less than 11.9 gallons.
     
  6. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    1,816
    1,660
    1
    Location:
    BOY
    Vehicle:
    2012 Prius
    Model:
    Four
    Bill norton said to slow down for better mileage, now who to believe.
     
    CR94 and Mendel Leisk like this.
  7. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

    Joined:
    Oct 17, 2010
    32,776
    21,766
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Oh I missed that. So @bwilson4web's chart is out to lunch? :confused:

    Updated MPG vs MPH chart | PriusChat
     
    Grit and CR94 like this.
  8. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    12,008
    5,626
    90
    Location:
    Western Washington
    Vehicle:
    2012 Prius
    Model:
    Three
    (1) It doesn't use the full 11.9 gallons when guesstimating fuel range. A couple gallons are set aside as safety margin, so it is computing from somewhere in the 9.x gallon range. Doing otherwise would result in a lot of angry calls to customer support when the car runs out of fuel after the driver sees a range guesstimate that saying the car could make the trip, when the car could not foresee the many non-average fuel-sucking conditions that drivers often encounter.

    (2) When your mpg consumption says 47 mpg, you are probably really getting only 44. Though this doesn't explain why you are seeing full-tank displays of 3xx miles.

    (3) How much fuel range are you actually getting? Note that you don't know its true fuel range until the engine actually quits from fuel starvation, stranding you along the road, possibly in the middle on nowhere. Bring along a spare can of fuel when testing this. Maybe a cell phone too.

    ??? What makes you think this? Most of the rest of us already know that recent MPG history is part of the range guesstimate-forecast calculation.
     
  9. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    1,460
    503
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    Nope. I'd rather trust BWilson's data.
     
    Mendel Leisk likes this.
  10. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

    Joined:
    Oct 17, 2010
    32,776
    21,766
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I was being smarcastic, lol.
     
    RMB, Grit and CR94 like this.
  11. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    1,816
    1,660
    1
    Location:
    BOY
    Vehicle:
    2012 Prius
    Model:
    Four
    According to bob wilson, you should be getting 62 mpgs at those speeds, when was your last egr cleanse?
     
    Raytheeagle likes this.
  12. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    812
    528
    0
    Location:
    Indian River County, Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    I don't know who bob wilson is, or care, It showed 54.something, but real mileage was 52. I'm very happy with that!
     
    #12 ASRDogman, May 15, 2019
    Last edited: May 16, 2019
    Raytheeagle likes this.
  13. ALS

    ALS Active Member

    Joined:
    Jul 15, 2009
    542
    240
    0
    Location:
    Pittsburgh
    Vehicle:
    2010 Prius
    Model:
    III
    I've checked my mileage against Bob's chart over the years and it's almost dead on to my actual fuel mileage at the same speeds. Now I've never driven my Prius over 65 mph so I can't tell you what I get at 70-75 mph.

    The mpg is measured with a calibrated Scan Gauge not the HSI.
     
  14. Triparadox

    Triparadox Junior Member

    Joined:
    Mar 12, 2019
    46
    10
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Three
    I poured about 8 gallons I think. I would never fill it when there's only 1 bar left. Too risky. It was probably around 3 or 4 bars left.
     
  15. Triparadox

    Triparadox Junior Member

    Joined:
    Mar 12, 2019
    46
    10
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Three
    My Prius is the standard one. Not the Prius C...
     
  16. Triparadox

    Triparadox Junior Member

    Joined:
    Mar 12, 2019
    46
    10
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Three
    Recently bought it. I have put around 1,000 miles only IIRC
     
  17. Triparadox

    Triparadox Junior Member

    Joined:
    Mar 12, 2019
    46
    10
    0
    Location:
    California
    Vehicle:
    2010 Prius
    Model:
    Three
    1. Ah, then it makes sense. So basically even if it reach 0 miles left, the car can still run for about 50 or more miles technically?
    2. Yeah, I wonder that as well.
    3. Fuel range was about 340 or so I believe. I couldn't remember the exact number since it's been a while.
    4. The reason why I think of it like that is because I have been driving several used cars back in my country. Of all those vehicles, no matter my driving style, when I top off the gas tank it will give me about the same range. That's why I thought the maximum range is not determined by driving habit, but programmed. Basically if the indicator shows about 80%, then the program will calculate the maximum times the percentage, giving about consistent result.
     
  18. Mendel Leisk

    Mendel Leisk Sidewalk Supervisor

    Joined:
    Oct 17, 2010
    32,776
    21,766
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    And your mpg of 47, that is what the car displays? I've found displayed 7.5% optimistic on average, so calculated would be around 44 mpg

    44 (mpg) times 8 gallons yields around 350 miles (range).
     
    fuzzy1 likes this.
  19. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    78,122
    33,002
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it shouldn't be figuring it on 8 gallons though? i thought estimated range was based on displayed average and x gallons (toyotas usable amount without safety)

    assuming the cars computer knows the actual average mpg's (not the fake o meter) i suppose it could be using 44 instead of 47. but i think it should be multiplying by 10 gallons or so.
     
  20. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    1,816
    1,660
    1
    Location:
    BOY
    Vehicle:
    2012 Prius
    Model:
    Four
    When I drive 25 miles pass DTE @ 0 and gas up, it’s usually 9.9 gals of gas dispensed at the pump to fill’r back up. So I know I can at least drive roughly another 100 miles after DTE 0 if life depended on it.
     
    RMB likes this.
Loading...