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Real Gasoline, not Ethanol

Discussion in 'Gen 2 Prius Fuel Economy' started by Daryll's Prius, May 24, 2011.

  1. rebenson

    rebenson Member

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    talk to the ethanol entusiasts and no difference in MPG. They also lie...
    In area I live near Chicago, there is no E0 stations. With the 14 Billion gallon mandate, not sure how long e0 will be available.
     
  2. wjtracy

    wjtracy Senior Member

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    ...refresh my memory on the 14 billion gallon madate...how does it work?
     
  3. litesong

    litesong Active Member

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    Yes, there is no 100% gasoline near Chicago, as it is in the majority of large cities. However, there is 100% gasoline stations nearer than Milwaukee, Bloomington, & Indianapolis.

    Go to pure-gas.org for commentary, addresses AND A GREAT MAP that you can zoom in, for more detail of stations selling 100% pure gas in Canada & the U.S. :cheer2:

    Gov't & the ethanol industry says 10% ethanol blends only lose 2 to 4% mpg. However, many drivers report a 10+% difference from 10% ethanol blends. With accurate past 10% ethanol blend mpg records & present 100% gasoline mpg records, our 3 cars show an increase in mpg of 7-8%, 7-8%, & 6% with our engines being smoother.:cheer2: Also, we don't have to shift down as much while ascending hills, because our cars have more power. :cheer2:

    Gov't & ethanol industry only account for the btu loss from 10% ethanol blend. However, I think the ethanol causes burning outside the most efficient setting for engines. Engines were designed to run at their most efficient on 100% pure gas.
     
  4. litesong

    litesong Active Member

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    There are 136 stations selling 100% real gasoline in Oregon. One station south of Seaside sells it, but only with a Pacific Pride Card Lock. PACIFIC PRIDE
    Jackson And Son Oil 84721 Happel Lane, Oregon.

    Go to pure-gas.org for other addresses & the great zoomable map of the U.S. with stations selling 100% pure gas.
     
  5. uart

    uart Senior Member

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    I'm no great fan of ethanol fuel and I only use it occasionally myself. But I still find it hard to believe those people that report huge increases in fuel consumption over 10%.

    I can believe 6% to 7% increases in fuel consumption (reductions in fuel economy), but the guys that are reporting stuff like 15% and 20% I'm totally skeptical.

    I'm usually averaging 4.3L per 100km (about 55 MPG) over a full tank, and since there's no tank bladder here I can run close to the full 45L or about 1000km per tank. So my tanks averages are remarkably consistent, typically only varying by +/- 0.1 L per 100km.

    In the past when I've run a tank of E10 the fuel consumption has usually only risen by 0.1 L per 100km, or about 2.3% (over what I was expecting based on previous non-ethanol fills). This measurement however is not all that accurate as the resolution is only 0.1 (2.3%) and the noise is also about +/- 0.1 (+/-2.3%). Still over several tanks I mostly only observe 0.1 more fuel consumption so it's probably somewhere near the mark. Given the low resolution of the measurement however I'd have to concede that it could be as high as 0.2 L/100km increase (4.6%).

    Interestingly my most recent tank of E10 (about 2 months ago) yielded 0.3L/100km higher fuel consumption, or about 7%. That tanks was more of the exception than the rule in my case however.

    Anyway, in the name of science, I filled with E10 again today (though at a different fuel station to where I got the previous worst MPG tank). Since my wife will be driving the Prius for the next week I wont tell her that it's E10 (to make it a blind test) and I'll report back whether or not the fuel consumption is worse than expected and by how much (compared to my usual non-ethanol fills). :)
     
  6. uart

    uart Senior Member

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    Update on my current E10 test tank. At 245km it's displaying 4.3L per 100km, so far this looks pretty close to normal (remember I'm not driving it - and the driver has no idea about the E10 or that this is a test). There's still about 750km to go on this tank so I'd don't know how it's going to end, but I'm sure that any discrepancy is much less than 10% or I'd already be seeing it by now.
     
  7. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Silly question, but are you sure that you are pressing "Reset" after every fillup? The odometer part automatically resets, but the fuel economy is a lifetime average since last Reset. So it won't change much the longer it has been since reset.
     
  8. uart

    uart Senior Member

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    Yep, the 2004 and 2005 models automatically reset the MPG calculations each and every fill, so you don't even get the option of "lifetime" averages. They changed that behavior with the later models.
     
  9. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    Also just something to add, the controls are loose on the experiment, so don't expect anything conclusive. It needs to be a length of time with E10 not just a tank here and there. Anything from temperature to wind speed all effect the results.

    Showing 0% difference is known to be physically and chemically inaccurate, which highlights the lack of controls. Still a good experiment, but there needs to be many more samples with which to average.
     
  10. uart

    uart Senior Member

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    There is no 0% here yet. The test is over 1000km and as yet I've only cover 250km. The test is over the course of many days over the same route, and weather variations tend to average out.

    Also I never mentioned 0%. I said that when I've conducted this test previously that it's typically only 0.1 L/100km higher than normal, which corresponds to about 2.4%. On one tank I used an extra 0.3 L/100km, which corresponds to about 7%, though that result was more atypical.

    Yes it's still not very accurate, I've already admitted to that. The resolution is 0.1L/100km and the "noise" (typical level of variation that I get per tank even with the same type of fuel) is +/- 0.1 L/100km. All I'm really trying to confirm is that the real world loss of MPG with a Prius is somewhere around 2% to 5%, and not the huge >10% figures that some people toss around. (Not that I'm calling people who make those claims liars, more that there is something wrong with either: 1 - Their Prius. or 2 - Their methodology. or 3. The quality of the E10 fuel sold in their area.)
     
  11. babybird

    babybird Member

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    Definitely not worth running it where I live since the only 85 octane I can get locally costs about $1.00/gal. more than the more expensive E10 stations in my area, and over $1.25/gal. more than the cheaper stations. There's no way in hell I'd be able to make up enough to make it worth running that-- I'd have to get like an extra 20 MPG out of it, which from 60 MPG would be a 33% increase. It would pretty much have to be nuclear fusion or something to get me that kind of improvement.

    I have no idea why they're charging so much more for it other than it's only available at the local airport instead of an automotive station.
     
  12. uart

    uart Senior Member

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    So you're saying E10 is $1.00 to $1.25 cheaper than non-ethanol Regular gas in your area? Wow that's a big price difference! E10 is only 3 to 4 cents per litre (about 10 to 15c per gal) cheaper than regular non ethanol petrol here.

    Or is that just some crazy pricing on 85? What about pricing compared to regular 87, that's the usual octane rating of regular gas in the US isn't it?
     
  13. Mike500

    Mike500 Senior Member

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    You are more likely to get less ethanol in reguar gas than mid-grade or premium.


    Unless you need the "octane" rating for the particular vehicle to prevent "pinging," it Premium is NOT better.


    Gasoline is composed of hydrocarbon chains of 6, 7, or 8 carbons linked together. Octane means the mix ratio contains more 8 chain carbion molicules. Higher octane means that it will not "pre-detonate" under higher pressures under higher compression ratios.


    It does nothing for lower compression engines.


    Under usual conditions, I do not purchase premium because;


    It is a slower seller, which means that it is less "fresh" than regular and has been in the underground tank longer to collect more water through condensation.

    To achieve higher octane, premium has a larger percentage of ethanol.

    If you look on the pump at the gas station, there is a sticker saying that it can contain up to 10% ethanol. Ethanol provides less mileage and collects condensation water more than gas without or with a lower precentage of ethanol in the mix.


    Ethanol must be used, since MTBE (methylbutyltertiaryether) as an octane booster was banned in 2005 in many states in that it contaminated ground water.


    So, regular is better functionally and financially in any model Prius.
     
  14. sub3marathonman

    sub3marathonman Active Member

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    Based on my observations of a mpg increase of 3 mpg, or about 6%, I am wondering if there is less ethanol in the regular gas now than just a few months ago. I know about the weather and all the other factors affecting mpg, but this seemed to be a significant jump at one fill-up which has continued for a couple more tanks. And it happened with the Prius my mom drives too.

    If this is correct, wouldn't that explain the about 10% price jump in gasoline, since there would now be about 10% more gasoline and less worthless ethanol that had the price subsidies?
     
  15. uart

    uart Senior Member

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    Update again. I'm now at 980 km with one blinking pip. The final result is estimated at 0.1 to 0.15 L/100km worse than the average of my previous few tanks of regular (non ethanol) petrol. This corresponds to around 2.5% to 4% worse fuel economy, based on my 4.2 L/100km average.

    Obviously over just one tank it's not meant to be a really "tight" test. But I've done this test several times before with very similar results, so I'm pretty sure that I'm somewhere in the right ballpark here. I did have one tank in the past where the loss was 7%, but that was the odd one out. Averaging my results over the half dozen times that I've conducted this test (and yes even including the suspect 7% tank) I'm at about 3% to 4% loss for E10. These result agree with "theory" and what the experts tell us about E10. Sorry but I've got to say that, based on my results, I'm pretty skeptical about the people who claim to be losing greater than 10% of their fuel economy. (seriously I've seen people claiming anything up to 25% loss with E10 ??)

    BTW. For the record I don't normally run E10, I prefer non-ethanol regular petrol (gas). I do like to run the occasional tank of E10 though (every few months), as a bit of a cleaner. When I do this I sometimes scrutinize the fuel consumption a bit and try to estimate the effect of the ethanol on fuel economy.
     
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  16. litesong

    litesong Active Member

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    I never ran comparisons between 10% ethanol blends & 100% gasoline until the 3rd tank using the same fuels. When running your occasional tank of 10% ethanol blend, do you fill your gas tank with a bare minimum of 100% pure gas(well under a gallon) remaining in the tank or are you still carrying 2 or 3 gallons of 100% pure gasoline?

    I don't believe your 2.5 to 4% difference between 10% ethanol blend & 100% ethanol-free gasoline, which accounts only for the btu difference between 10% ethanol blend & 100% pure gasoline. Your figures are the same figures as the ethanol industry states, & they have a money making reason to say what they say.

    To be able to take advantage of the extra octane of ethanol, an actual ethanol engine has a very very high compression ratio. Using the latest technology of direct fuel injection, an ethanol engine can rival compression ratios nearly has high as diesel engines. Of course, engines designed to run 100% pure gasoline have dramatically lower compression ratios causing ethanol to be a poor choice for such engines. I'm sure there are differences between ethanol & pure gasoline as far as preferences for Bore & Stroke dimensions, too.

    With many years of accurate 10% ethanol blend records & 7 months of 100% pure gasoline records, our 3 cars(even through our colder northern winter) show mpg increases of 8%, 7-8%, & 6%, 100% pure gasoline over 10% ethanol blends.
     
  17. ralleia

    ralleia Active Member

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    Only this spring did I learn that ethanol has 30% less energy than gasoline. Around here the E10 89 octane is usually 10 cents cheaper than the straight 87 octane gasoline. I started doing the math and determined that the E10 was not economical based on the reduced energy.

    I'm also finding a greater delta than the theoretical difference in energy between the two fuel types. I'd been tracking in fuelly last year when I was using the E10 and got at average of 22.9 mpg in my '09 Toyota RAV4.

    I've been fueling with straight gas for the last couple months but feel I need to start a different fuelly RAV4 to track this one. My dash stats have been reading about 25.3 mpg in the months since I've gone to straight gas. The hand-calculated number for my last fill-up is 25.4 mpg, so the dash stats appear to be pretty much dead-on.

    This amounts to a difference on my experienced fuel efficiency of 9.8% greater efficiency on straight gas as compared to E10.

    [​IMG]

    [​IMG]
     
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  18. uart

    uart Senior Member

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    I suppose some of that difference could be attributed to warmer whether with the more recent 100% gasoline fills.

    Yes E10 would certainly be a con if you truly get 10% less mileage. They may as well dump the whole ethanol content down the drain and give you just the remaining 90% gasoline, you'd be just as well off. This is one of the reasons I'm skeptical of these very poor E10 results - never the less people keep reporting them so there must be something in it. :confused:
     
  19. ralleia

    ralleia Active Member

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    All the reporting for the E10 was for the months of October and November when it isn't too chilly here. It doesn't usually get too bad until January and February.

    Still, part of that figure for the E10 can probably be attributed to the weather. Perhaps when we do our road trip later this month I'll try to fuel up with one type of gas on the trip out and another on the trip back.

    The difference in elevation is about 500 feet over 750 miles each way, so maybe I'll spot the E10 an advantage by using it on the trip "downhill? " ;)
     
  20. litesong

    litesong Active Member

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    Yes, you will get better mpg than the 2-4% the ethanol industry & gov't tells you.

    Go to pure-gas.org to find the addresses of the minority of 5100+ stations & details, still selling 100% ethanol-free gasoline in the U.S. & Canada. There is also a great zoomable map showing the stations. The greatest density of stations is in the Southeast U.S., with a smaller concentration west of the Great Lakes.

    Ethanol engines has much higher compression ratios than gasoline engines, to take advantage of the high octane rating of ethanol. Ethanol in a for-gasoline designed engine doesn't get its full efficiency(duh!).

    I don't get your 9.8% increase in mpg using 100% ethanol-free gasoline, but 2 of our 3 cars, set their all time highest mpg within 3 weeks of switching to 100% gasoline. Also, those cars are getting 7-8% & 8+% better mpg. Our 3rd car gets 6% better mpg using 100% pure gasoline.

    Also, all 3 car engines run smoother(1 engine manually shifts much better than with ethanol), quieter, & less downshifting is needed ascending hills.

    Yes, leave the ethanol for ethanol engines. Better yet, leave the ethanol in the crops so poor people can eat, instead of seeing their food fed to engines.