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

91 Ethanol Free Findings....

Discussion in 'Prius v Fuel Economy' started by G Man v5, Feb 14, 2015.

  1. G Man v5

    G Man v5 Member

    Joined:
    Jan 15, 2015
    158
    41
    0
    Vehicle:
    2016 Prius
    Model:
    Two
    It is difficult if not impossible to find ethanol free gas in the St. Louis area. So while in Columbia, Mo. last week I filled up...Not for the higher Octane, but to see if the "pure gas" would make a difference. 91 Octane "pure" gas. (I like corn but not in my gas)

    Average 41.42mpg (real) 44.0 on the car meter. As I've only filled up twice previously, with real world mpgs at 42.6 and 43.2, it was no better. The ambient temp was a bit colder this week, so I believe the temp did have a bit of effect on the rating...
     
    #1 G Man v5, Feb 14, 2015
  2. wjtracy

    wjtracy Senior Member

    Joined:
    Sep 19, 2006
    11,340
    3,596
    1
    Location:
    Northern VA (NoVA)
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Thanks for reporting to us.
    St Louis is an EPA reformulated gasoline (RFG) region, which explains the lack of E0 (same here).
    Typically RFG is a little lower energy content, so you might see a little better MPG just getting outside of the immediate region. If your base case is RFG E10 (St Louis) then the E0 outside St Louis almost certainly has more energy content (min. +3%).

    What I do by the way is get exactly 1.5 gal sample in my lawn mower container and measure grams, whereas energy content relates to weight/vol density. But I don't do this too often since I live in RFG region, so not much variation, and when I am traveling, its a pain to carry my smelly gasoline can.
     
    #2 wjtracy, Feb 14, 2015
  3. rdgrimes

    rdgrimes Senior Member

    Joined:
    Jun 7, 2013
    1,740
    446
    4
    Location:
    New Mexico, USA
    Vehicle:
    2018 Prius Prime
    Model:
    N/A
    Been a long time, and not a very relevant study, but some years ago I did 5-tank samples in my Tacoma V-6 4x4. Compared premium, regular and regular with Ethanol. (15 tanks total). There was no difference between premium and regular, but the reg with Ethanol yielded roughly a 0.5 MPG decrease in MPG. I think I sampled enough tanks to rule out other factors.
     
    #3 rdgrimes, Feb 14, 2015
  4. jejb

    jejb Member

    Joined:
    Jun 11, 2014
    95
    27
    0
    Location:
    NW Ark
    Vehicle:
    2016 Prius v wagon
    Model:
    V
    E0 is very easy to come by where I live. So I tried several tanks of regular E0 in the Prius. I did not notice any real difference, certainly not enough to justify the about 15% increase in price over E10.
     
    #4 jejb, Feb 20, 2015
(You must log in or sign up to post here.)