Ethanol worth mileage drop?

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

  1. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Herm . why would you need a "cheap octane boost " ? What sort of vehicle are you driving ? Mine runs fine on 87.
  2. Carcus

    Carcus Well-Known Member

    If your looking for straight gas, there is a list of ethanol free gas stations in the U.S. and Canada here:

    If you're concerned about the amount of ethanol you're getting mixed in with your gas you can buy a test kit here:
  3. Carcus

    Carcus Well-Known Member

    I recently switched from QT to Exxon fuel on three different vehicles -- two motorcycles (both carbureted) and a pickup.

    Both motorcycles are running better, I can turn the choke off immediately after start and they both idle fine. Couldn't do this with QT gas, ... had to wait a minute or so for the bike to warm. Any "pinging" tendancies have gone away and the older bike (Goldwing) just feels like it has more power. MPGs appear to be up on the Goldwing, not enough miles on the other to know, the pickup has shown an improvement of at least 5% on mpg. I cannot tell that the pickup ('09 fuel injected) runs any better, other than the mpg improvement.

    I used to think gas was just gas, I don't think that way any more. I suspect that the difference I'm seeing is due to the amount of ethanol in the mix but I really don't know. Both stations advertise "less than 10% ethanol".

    I'll buy from said Exxon station for now. In the future I'll be quicker to suspect bad gas if I notice performance problems (pinging, rough idle, down on power, sub-par mpg) and switch stations if necessary.
    Last edited: Oct 1, 2011
  4. Carcus

    Carcus Well-Known Member

    Having scoured the internets on this subject for more time than I'd like to admit, I've read:

    The "official" word on E10 is that you'll lose very little mpg, something like only 2% or less. But there are a LOT of people -- many with detailed records -- reporting more, in some cases even 10% or 15% loss in mpg.

    My take is that there are so many variables at play there is no single answer on what effect ethanol will have. Some of the major factors are:

    How much ethanol is really being mixed (are you actually buying E2, E6, E10, E12, E20 .... )?
    How long has the ethanol been around.
    How much moisture (humidity) has the ethanol been exposed to.
    Carbureted or fuel injected
    Newer tech injected (i.e. 2005+) vs. older.
    What kind/how much additives are the individual refiners and distributers adding to the mix?

    To me, the bottom line is you have to experiment around with different stations and see which one works best for you, and be ready to change and seek again if you think you've got a problem.

    I would not let an engine sit more than 3 months (especially if it's carbureted) with e10 in it. And if you do at least put some stabil or similar in the tank.
    Last edited: Oct 1, 2011
  5. herm

    herm Well-Known Member

    if your car does not ping with cheap gas then by all means use it, but note that many modern cars will adjust the ignition timing if they detect any pinging at all, and that will reduce your gas mileage if the car is slow to readjust after the pinging stops, thus false economy. I prefer to buy my gas at a quality gas station, its not that much of a difference.
  6. Rackster

    Rackster Well-Known Member

    Thanks for doing the research. I can say that I've done the same thing; deep dives on the internet to research an item/problem. You can pull a single thread and end up finding another two or three to dig into!!

    I suspect that I'm down 10% on my MPGs since the winter grade gas came out, maybe more. Power seems to be the same though. I have a 2000 Ranger, so I may not be able to leverage the blended fuel like the 2005 and older vehicles can. I was wondering if there was an additive that would offset the effects of ethanol, but what would be the point I suppose.

    I got an Ultragauge for Christmas, so my studies are restricted to the ethanol blended fuels for the moment. That said, I can still see a significant difference in the FE when compared to my summertime data and commonality with the data from last winter's studies. I will take your advice and shop the gas (using the major providers) to see if there is a difference. It would offset the need to pay more for an additive.

  7. herm

    herm Well-Known Member

    A carburated engine will get all gummed up after a while, but a fuel injected system seems to handle sitting unused for a long time. I think carburators are not as well sealed and the good stuff evaporates after a while, .. if its gasohol then you get moisture build-up.
  8. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    That stuff just claimed the (rather low quality) carburetor on my snow-blower after 4 winters of use. :( $60 to replace with a non-sealed unit so I can actually clean it next time. :rolleyes:

    On the other hand, my LawnBoy has been just fine for the last 6 years.
  9. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Sean , by any chance is your LawnBoy a 2-stroke running premix ? That oil-gas mixture may be protecting your carb from ethanol damage. I'm just guessing.
  10. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    Nope, it's a 4 stroke running straight fuel from the pump. It starts on the first pull every time, too.

    Must be the Honda engine. ;)
  11. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    True fact. I borrow a tiller for the garden each year from a friend. The thing is a big heavy beast, built when Carter was in office. Still starts on the first pull despite sitting most of the year. Honda 4-stroke engine.
  12. herm

    herm Well-Known Member

    does it sit with the carburator and tank drained?.. but I agree, Honda makes great small engines.
  13. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Oh, yes. He takes good care of his machines. I also sometimes borrow his 1994(?) Toyota truck with 250k miles.
  14. Right Lane Cruiser

    Right Lane Cruiser Penguin of Notagascar

    I make sure I run mine dry at the end of the season every year. I didn't manage it for the snowblower last year and ended up paying for it. :p
  15. jatkeison

    jatkeison New Member

    A mechanic who worked on my 2007 Prius told me that he has detected ** 50% ** ethanol in the "gas tanks" of some vehicles he has worked on.
    He made that comment in response to my query about why my mileage had dropped 10%...
  16. herm

    herm Well-Known Member

    is there E85 in your area?, that is probably what he saw.

    Only some modern cars can tolerate E50 without lighting up the check engine light.. usually the fuel injectors cant deliver enough volume to richen up the mixture to what it needs.. the computers will not allow the engine to run so lean and will go into failsafe mode, killing your mileage or just stopping the engine, at best. E20 is not usually a problem... you can use ethanol to fine tune your mixture and timing if you know what you are doing.
  17. diamondlarry

    diamondlarry Super MPG Man/god :D

    Yeah, and just think what will happen if the jokers that want to increase the amount of poison-aka ethanol-to 15% get their way.:rolleyes::mad:
  18. Carcus

    Carcus Well-Known Member

    I just filled my tank with 89 octane E0. Didn't cost any more, was actually 5c less than nearby stations E10 89 octane.

    Too early to tell (only 50 miles in) but preliminary indications are an mpg gain of somewhere between 5 and 10% (?).

    We'll see.
    Last edited: Aug 3, 2012
  19. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    I wonder what he used to detect and measure it.
  20. diamondlarry

    diamondlarry Super MPG Man/god :D

    There are kits available for measuring the amount or, you can make a simple version using a clear container with evenly spaced lines that would give you fairly accurate reading.

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