Ethanol worth mileage drop?

Discussion in 'Emissions' started by wannabeclean, Oct 25, 2006.

  1. Zukiru

    Zukiru 0.29 coefficient of drag

  2. Yaris Hilton

    Yaris Hilton Half a Bubble Off Plumb

    I have a very, very hard time believing that anyone's getting the huge mileage drops some have reported on here simply from switching to E10. I've used it off and on since 1976 (when it was a limited availability novelty called "gasohol") in a wide variety of vehicles from early 1970s 7L carbureted American V8s to an old 1963 Panhead Harley-Davidson motorcycle to current fuel injected, computer controlled cars. I've never seen any driveability issues, noticeable fuel mileage decrease or fuel system damage in any of them. Point's moot here as all gas at the pumps now is E10, but I see no reason to bemoan that fact.

    As for mileage, I'm not a real hypermiler, just a reasonably sensible driver. On E10 my new Yaris 4D AT sedan got 37.5 MPG on its second tank driving mostly in town (haven't filled it since), and my big 1998 Mercury villager van consistently averages about 20. The 1995 Volvo 850 Turbo I just traded off got 19-21 MPG with my mostly around-town driving, frequently briefly getting into the turbo boost with a fairly heavy foot. (It was a blast!) None of those numbers are going to get me bragging rights on a hypermiling board, but I'm not ashamed of them either. The Volvo and Villager were around before and after the E10 changeover, and it didn't affect them. (Out on long highway trips they both average in the 28-29 MPG range, running at Interstate speed limits, heavily loaded for family vacation travel.)

    If someone's dropping their mileage by a third, something's wrong with their car or their driving other than just putting E10 in the tank.
  3. Yaris Hilton

    Yaris Hilton Half a Bubble Off Plumb

    Oh yeah, I clean forgot the 1940 Ford Fordor Deluxe with stock Flathead V8 that I used to sometimes run on gasohol. It liked it just fine, too.

    There was a time when premium gasoline with suitable octane for older high-compression engines wasn't readily available. The gasohol had a higher real octane number than the generally available unleaded, and some stations still had leaded regular. 1 part leaded regular to 2-3 parts gasohol used to keep the old Harley and premium gas burning 10.5:1 compression 429 Ford running knock free when the recommended fuel was unobtainable.
  4. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    My 6 tanks last summer with E10:
    Average MPG: 62.8
    Average temp: 85F

    My 6 tanks since then, with straight gas:
    Avg MPG: 64.1
    Avg temp: 60F

    According to my records, the drop from 85 degrees to 60 is worth about 3 mpg loss. Compensating for that puts E10 down by about 4 mpg over straight gas. 4 mpg / 60 = 6.7% drop from E10.

    I report, you decide.
  5. JusBringIt

    JusBringIt Be Inspired

    Different cars are affected differently. Sometimes the mix may be more that 10% ethanol which have been reported though not very often this happens.

    Though it may not be correct to attribute the loss entirely to ethanol, the losses can still be accounted for in some models.

    It makes about a 10% difference in my car.
  6. 99LeCouch

    99LeCouch Well-Known Member

    I see my car getting about 5% less economy with ethanol-laced gas. I'm consistently able to push 500 miles per tank on my land yacht on straight gas, while with ethanol gas I was lucky to see 450 per tank.
  7. hmiwb

    hmiwb Member

    I'm for alternative fuel, but I can't support replacing food crops with fuel crops. We've got to export something and our food exports help feed the world. We can get more fuel efficient and get the same results in cutting our oil imports. There's so much room for improvement in fuel efficiency in this country.
  8. melinuxfool

    melinuxfool Well-Known Member

    I don't remember where I heard this, and can't really verify this, so take it with a grain of salt. But I had heard with older cars, like first generation of OBD-II, take a greater hit from ethanol than newer cars. The reason I've heard is the ethanol sort of "tricks" the O2 sensor into thinking the car is running lean, when it isn't, so more fuel is squirted into the cylinders to compensate, making the car run rich and reducing fuel economy.

    So on older cars, it might not be worth it. From an emissions standpoint, I haven't a clue, because I've never even had a car checked. The state of Maine doesn't do emissions checking.
  9. diamondlarry

    diamondlarry Super MPG Man/god :D

    I think the biggest reason for the drop is that there is less total energy in ethanol so it takes more of it to do the same work.
  10. lxmike

    lxmike Well-Known Member

    Down here the boaters don't like it at all. says there getting seperation and water in there fuel tank when it sits too long.
  11. R.I.D.E.

    R.I.D.E. Well-Known Member

    I think 10% is about right since E10 has about 96% of the BTU of pure gas. Driving to Detroit last time I bought straight gas in Pennsylvania and hit just under 40 MPG, which was the best tank ever in the 06 Corolla with AT on the highway.

    Not sure if there is any place in Va without E10 anymore.

    In some cars the higher octane rating of E10 versus regular would allow timing advance and possibly some offset to the lower BTU content. Wish I could get some straight gas for the Insight CVT and see what the difference was compared to my local trips on E10.

  12. Yaris Hilton

    Yaris Hilton Half a Bubble Off Plumb

    "Straight gas" isn't anymore. It just has different "oxygenates" in it, like TAME, diisopropyl ether, isopropyl alcohol or butanol. The only difference as far as mileage is concerned is that most "oxygenates" are blended to a concentration giving a maximum of 2% oxygen in the blend, whereas ethanol has an exemption and 10% ethanol gives about 2.9% oxygen, thus a bit lower total energy than the other "oxygenate" blends.
  13. uabcar

    uabcar Well-Known Member

    Question- I assume the car manufactures are give a standard gas formula to when doing the EPA/CAFE mileage testing?

    It seems that over the last few years corn oil enriched gas has gone from being just an option to the only thing available in may/most(?) states. It seems to me that reducing the energy content of gasoline at the same time as increasing MPG requirements makes the achievement of better FE (as measured by MPG) for a doubly difficult task. The best way to normalize things would be to measure miles driven per 000's of BTU's.

    That said, while researching for this post I cam across the attached article. Apparently the manufacturers are not as far off of the 35.5mpg fleet avg as you might think. I suspect you all already know most of this but the CAFE vs EPA calc differences. I knew about the fleet vs per vehicle aspect but I wasn't aware of the CAFE formula not changing since 1975.
  14. Yaris Hilton

    Yaris Hilton Half a Bubble Off Plumb


    Another quirk a lot of people don't know is that the fuel consumption is figured backward from the carbon emissions out of the tailpipe. Seems odd, but if you remember anything about hidden fuel supplies in NASCAR racers, you'll understand why.
  15. oilburner

    oilburner Active Member

  16. The Doctor

    The Doctor Old Dude, New Car

    In the owners Manual for my Suzuki SX4, 2.0L DOHV engine, it states that Ethanol mixed fuel is OK, if the % of ethanol does not exceed 10%.

    Ethanol does burn with fewer emissions, which is why it's mandated by law here in Florida, but.... it also has less energy per unit when compared to regular gasoline.
    So by burning "Gasahol" we produce less emissions but get less performance out of our cars. It's not a trade-off I'm really excited about.

    I'd love to be able to get just one full tank of real 100% gasoline and just see how much better performance and MPG I could get.

    On the plus side, Ethanol does function as an Anti-Knock additive and it also prevents gas line freeze in cold climates. I was glad to use it when I lived in Illinois, in the winter.

    Cheers mates!
    The Doctor :cool:
  17. herm

    herm Well-Known Member

    Here in Miami you can buy non-ethanol gas at the pump, its intended for boats and they will charge you about a buck more per gallon.. look around your town since Central Florida is the land of lakes and everybody has a bass boat :)
  18. The Doctor

    The Doctor Old Dude, New Car

    Actually there are a few little lakes around this part of FL, but I don't remember seeing any Boat Only gas pumps. I would probably have to go all the way to the Gulf to find a boat dock with non ethanol gas. The total cost for the effort would definitely negate any improvement in performance for my car.

    Interesting thought, but not practical for my car.

    Thanks for the thought.

    The Doctor :cool:
  19. 2RR2NV

    2RR2NV Ultimate Newbie

    for me, E10 and regular gas has been a wash. i buy gas where/when it's cheapest at the time i need it. sometimes, it's cheaper on base, sometimes not. on base is E10, Walmart is not. i've been swapping between the 2 quite a few times.... since my trips are never always the same, i can't really quantify any difference in the Elantra. now, the Minivan, THAT i can tell a difference in mileage. E10 sux bahls! i've ran road/vacation trips plenty of times on the same roads doing the same speeds and E10 hits the pocketbook in a not so nice way. in a 1700 mile trip (with a few hundred miles driving around in WI), from SD to WI and back, saving $40-50 helps.

    I am a firm believer in Biofuels (& nuclear - fission, breeder, fusion - when it gets finally working well). E10 is NOT cheaper around here. it's pretty much the same price as regular gas. not worth it in my book.

    also, didn't know the nuclear plants produced pollutants.... i guess if you mean nuclear waste... then someone needs to shoot the tree-huggers and start building breeder reactors. wouldn't have to worry about waste then or where to store it.
  20. herm

    herm Well-Known Member

    The pumps are not labeled "Boat use only", in any case I have been using gasohol since Carter was president, and would go out of my way looking for it.. I like the cheap octane boost you could get out of it. I'm sure many cars dont tolerate E10 well, probably drives the oxygen sensor crazy until they adjust by richening the mixture.

Share This Page