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Prius III Performance Based On Fuel Quality

Discussion in 'Gen 3 Prius Main Forum' started by john burns, Nov 30, 2009.

  1. john burns

    john burns New Member

    Joined:
    Sep 19, 2009
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    Location:
    Jacksonville Florida
    Vehicle:
    2010 Prius
    Model:
    IV
    I just completed my 1st trip with my Prius III.

    But first let me say I had a 2005 Honda Civic Hybrid that I traded in when I bought my Prius. I loved my Honda and after learning how to drive it I was able to consistantly get 49 - 50 MPG as long as I kept in under 65 MPH. This time because of all the hype I tried the new Prius

    I have now put a little over 3500 miles on my new Prius since I picked it up in September. My best mileage to date has been 60.1 MPG on a tank of fuel as shown on the display. Calculated out I figured about 59 MPG. But of course it depends how much time you take to fit every drop of fuel into the tank when you fill it.

    Locally around Amelia Island in northern Florida I seem to get 58 - 59 consistently. Although I have to say that the area is semi rural, flat, speed limits 30 - 55 MPH, traffic light, and lights well spread out.

    This past weekend I went to Cincinnati Ohio and traveled the speed limit (55 to 70 MPH) as posted. My trip took me through Georgia (flat), South Carolina (semi flat), North Carolina and the mountains around Ashville (not flat). Because of a landslide on Rte 40, a major interstate I had to go directly through the Smoky Mountains in Tenn. (steep mountain roads), then on through Kentucky (rather hilly), into flat Ohio.

    I filled up or topped off the tank 4 times, although I could have made the round trip on only three tanks of gas. With the exception of one tank of gas I averaged 56 MPG, as shown on the display.

    Needless to say I am very pleased with the cars performance. Good gas consumption, comfortable and excellent handling under all road conditions.

    However, the purpose of my writing is to discuss quality of fuel. On one tank of fuel, (I always buy from a name brand large station where I am certain there is a good turn-over), I could not get the MPG over 45, no matter what I did. I must add this was on a relatively flat section of the trip. I have had the same issue with my 2005 Honda Civic Hybrid where I would occassionally got a tank of fuel that like this incident actually affected the performance of the car, significantly reducing the MPG. You do not feel the cars performance change, acceleration is still good, and engine runs smooth.

    I am just curious have others seen this performance variation?:confused:
     
    #1 john burns, Nov 30, 2009
  2. kgall

    kgall Active Member

    Joined:
    May 3, 2009
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    Location:
    Olympic Peninsula, WA
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Based on the computer or your calculation?
    I sometimes find (on my old car without a MPG computer) that my gas mileage on a tank will appear to be pretty bad.
    But, you guessed it--the mileage on my previous tank had been outstanding, allegedly.
    Course, during the intermediate fill up, I hadn't really filled up, so the mileage of the first tank looked better than it was and the second looks worse.

    Could this be what's happened to you?
     
    #2 kgall, Nov 30, 2009
  3. eaglesight333

    eaglesight333 Senior Member

    Joined:
    Apr 23, 2009
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    Location:
    Northern, IL
    Vehicle:
    2010 Prius
    Model:
    III
    The quality of fuel has been discussed a few dozen times in other threads. And you will get arguments from both sides. From my own personal experience with my previous vehicle, I do know that the gas quality/brand does make a difference. Others will disagree, but from what I have seen. i will never buy cheapo gas again.

    As also stated in other threads. Your MPG can be affected by multiple things. eg: gas mixture, weather, temperature, foot/gas pedal control.

    With the mixture itself, even if you get it from the same station, the mixture can differ slightly from tank to tank. No true way to know for sure, unless you have a chemistry set in your car.
     
    #3 eaglesight333, Dec 1, 2009
  4. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
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    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
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    Not on the Prius but I did on the smart. I drove it across the country and the smart requires premium fuel. I refuelled in middle-of-nowhere-small-town Saskatchewan which had a pump that had one filler and said "Regular" on one side and "Premium" on the other. Naturally the daughters of the owner of the store didn't know and just nodded if I asked if it was Premium fuel.

    Needless to say, I don't think it was as I lost 2L/100km and was the worst FE recorded on that trip and it was also the flattest part of the trip lol.
     
    #4 Tideland Prius, Dec 1, 2009
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