E10 RFG vs. Straight Gas test--final results

Discussion in 'The Daily Grind' started by lamebums, May 24, 2008.

  1. Zukibot

    Zukibot Member

    I'm in the same Oregon boat, and our county was mandated to use 10% Ethanol a few months ago.:(

    A decrease in MPG, especially now, really adds insult to injury.
  2. rweatherford

    rweatherford Times my Mileage by Six

    I have a post dealing with E10 - E30 in the Mazda section. MO has mandated E10 so no straight gas for me to compare.

    I did not find the mileage loss from E30 to be anything to bunch my britches when I was paying less for it. Unfortunately the gas companies have this figured out and have priced E85 in a way that makes it more expensive than regular E10 after you figure the mileage loss.

    I would still be running E30 blend except that the current price for E85 is quite a bit above what I have fuel contracted for @ $3.03 a gallon for E10.
  3. lamebums

    lamebums Member

    I just topped off with some of that corn **** before I leave Philly tomorrow, which is the center of E10 and RFG hell.

    The results were predictable: 5.452 gallons, 253.3 miles, 46.460 MPG.

    100 miles of Philly city driving didn't exactly help, but the tank average was never above 52 even when it was just all road miles at the beginning. Sg was off by only 0.05 gallons.

    My tires are down to 60 PSI for the trip tomorrow (the 100+ heat had them up to 74 when I measured them!) I'll get one, possibly two more tanks of corn by tomorrow night.
  4. lamebums

    lamebums Member

    Second tank of E10 - 50.159 MPG, 236.2 miles, 4.709 gallons. Had to top off before I got off the Turnpike, so I could be guaranteed it was E10 (They all are on the Turnpike so...) 95 degrees, A/C off, all road miles.
  5. lamebums

    lamebums Member

    Last tank:

    51.749 MPG, 470.5 miles, 9.092 gallons
    50.159 MPG, 236.2 miles, 4.709 gallons
    46.460 MPG, 253.3 miles, 5.452 gallons

    The second test of E10 (two tanks E10, one tank E10 RFG) is an average of over 19.253 gallons over 960 miles, or 49.862 MPG.

    This is consistent with the first test of E10 (49.600 MPG) with a similar proportion of city driving (about 20-25% overall).

    The FE loss with E10 is roughly 15%.

    Coming back from the gas station in Ohio I got 59.5 MPG over 18.4 miles (that included an elevation rise from 500 to 900 feet).
  6. rweatherford

    rweatherford Times my Mileage by Six

    I'm curious which of the above 3 tanks is which fuel? Interesting research either way. Since I can't get "regular" fuel I can't collaborate with you.
  7. lamebums

    lamebums Member

    The first one (46.460) was E10 from one of the Sunoco's on the Turnpike.

    The second one (50.159) was E10 RFG from a Getty or somesuch in Philly.

    The third one was also from a Sunoco E10, westbound on the Turnpike.

    The first one had about 50% city driving in it which explains the lower mileage. The other two however were almost entirely road miles.

    I've also concluded that RFG is indeed a small reduction in FE (1-2% perhaps?) but rather E10 is the killer.

    If you live <20 miles of a neighboring state it may be worth going to another state to get regular gas. Just crunch the numbers and assume a 15% FE gain from regular gas and whether or not it would be worth your while. That's what I do - drive eight miles into Ohio to get an extra eighty miles out of my tank.
  8. rweatherford

    rweatherford Times my Mileage by Six

    I have fuel contracted in my local town for $3.09. I'm not driving anywhere for fuel. Nearest state is 50+ miles each way and that is IL. Fuel is higher there.
  9. 2008Mazda3i

    2008Mazda3i Well-Known Member

    And what I hate is anymore in a metro area like DFW I can't find any place as of recent that doesn't use E10 :(
  10. lamebums

    lamebums Member

    I've uploaded a link to a gas map across the nation. It has the areas that are mandated to use some various crap in the fuel, if that helps. It's in my sig. (April 2007, so does not have Oregon on there, though. It's all E10 in that state now.)
  11. 2008Mazda3i

    2008Mazda3i Well-Known Member


    Thanks for the link but there is nothing outside of the metro area that isn't @ least 70 miles round trip it looks like. :(
  12. Damionk

    Damionk DWL Lover

    When I was filling up yesterday I happened to look at the side of the pump, and down toward the bottom on a sign that was about 1 ft square I see 10% ethanol. Crap. What's odd is it was positioned in such a way that it looked like they didn't want you to see it. They had it maybe about a foot up from the ground and behind those guards to keep people from running into the pumps on accident.:(
  13. Yarisman

    Yarisman Well-Known Member

    I drive a 2008 Yaris sedan and have tried the High Octane BP fuel, biting the bullet to pay the extra .25 for 3 tanks. I got an average of 33 MPG. I went back to E10 and am currently getting 40-42 MPG. With my 2006 Yamaha Vstar I tried the same experiment and went from 40-42 MPG to 48-50 MPG from 92 octane to E10.
    In Nebraska we have no access to straight gas, so I can't compare apples to apples, but am currently ok with the mileage I get on E10.
  14. donee

    donee Well-Known Member

    Hi Yarisman,

    High octane gas has less fuel energy per gallon. Most inexpensive octane boosters have much less energy per gallon than gasoline. So your experimental results makes sense.

    Similarily, Ethanol is one of those low cost octane boosters. And if you could get gas without it, you would see even better mileage.

    To get similar mileage with E85, one would need allot more compression ratio in the engine. And even modern engines do not have the variable compression ratio capability required by various Ethanol fractions.

    This is one of the great reasons why Butanol would be a better bio-fuel.
  15. warthog1984

    warthog1984 Well-Known Member

    Unless of course you ever need to drive in 10 degree weather. In which case your butanol vehicle isn't going anywhere.
  16. jcp123

    jcp123 Caliente!

    Around here, you don't even know. The pumps have stickers stating that this fuel may contain up to 10% ethanol.
  17. jimepting

    jimepting Well-Known Member

    Interesting map-and helpful too. But I don't understand several of the abbreviations. Conventional gas(white) seems pretty clear and obviously that's what we seek. What do the abbreviations RVP, CBG, N&S, GPA, MTBE mean?

    I'm currently in Memphis. Looks like I could get conventional gas by just driving slightly east.
  18. lamebums

    lamebums Member

    "May contain up to 10% ethanol" is best translated as "does contain at least 10% ethanol".
  19. some_other_dave

    some_other_dave Well-Known Member

    RVP == Reduced Vapor Pressure, or something like that, I think. If I'm right about that, it's "summer gas" and does not evaporate as easily.
    MTBE == Methyl Tertiary Butyl Ether; a fuel oxygenate that has fewer downsides than ethanol--except that it's [apparently; but there is some controversy about it] carcinogenic in large amounts, and seems to get into the water table... It has been largely discontinued.

    Not sure on the others.

  20. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Last edited: Jun 23, 2008

Share This Page