By on August 4, 2017

E10 + 100 Percent Gasoline at the Pump

Duncan writes:

My daily driver is a 2013 Hyundai Genesis 5.0 R-Spec (with about 22,000 miles), making a claimed 429 hp on premium gas (91 octane, I assume). The power dips to 421 hp (claimed) when running on regular. Here in Iowa, we have the luxury of purchasing fuel with no ethanol.

The 87 octane gas w/o corn costs almost as much as 91 with. If it was your money, what would you put in the tank? 87 with no ethanol ($2.40ish a gallon), 87 with ethanol ($2.20ish) or 91 with ethanol ($2.50ish)? Running 87 or 91 without ethanol does improve mileage, whereas I do not notice an increase in performance running 91 or 93 — though it is recommended (but not required) by the good folks at Hyundai.

Sajeev answers:

Oh, the irony of a reader in corn country having access to ethanol-free gas while yours truly, in the hub of big oil, lacks such variety. But I digress…

My love of pure gasoline comes from older vehicles with fuel systems ill-equipped to handle the corny stuff; also lacking the high-compression motors that (could) take advantage of that 2-3 octane number increase.

According to Google, your ride has a stout 11.5:1 compression ratio. In theory, you’d make more power with a computer reprogrammed for ethanol. In reality? Most folks won’t pay for a tune, and the quality depends on the person behind the laptop. Without the tune, with my Genesis seat time in mind, any high-octane power bump is offset by aggressive torque management at low throttle inputs. No worries for non-lead foot drivers: stick with low octane.

If increased power isn’t likely, let’s talk value via fuel economy and the price at the pump for low-octane fuel. Here’s the thing: nobody can armchair your driving habits. Combine that with knowledge of an R-spec Genesis’ computer parameters and who could possibly give a relevant answer? Odds are the $0.20 premium for 100-percent pure, low-octane gas isn’t a significant value proposition. But only you can put it to the test.

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

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74 Comments on “Piston Slap: Corny Fuel Talk from Iowa?...”


  • avatar
    ajla

    I hate torque management programming.

    As far as the question goes, I’d use 91 octane E10.

  • avatar
    notapreppie

    10% ethanol gas as roughly 3% less energy than pure gas. In your 25 mpg highway car, that’s 0.75 mpg difference (0.48 mph in the city). This isn’t enough for anybody without sensitive measuring equipment in control laboratory environments across repeated tests to tell the difference.

    Seriously, the normal variation in 99% of the population’s drive cycles across a tank of gas will be larger than that. I’d chalk up any small difference I saw/felt to confirmation bias.

    That 8 hp bump (2%) from using premium vs regular gas is even smaller. Honestly, I’d just run 87 with 10% ethanol and focus on enjoying the 400+HP 5.0L V8.

    • 0 avatar
      SCE to AUX

      +1. Given the data, it’s not worth messing around with anything but the cheap stuff.

    • 0 avatar
      MBella

      It depends on the vehicle. If it is premium recommended, then use that. It means the engine is tuned for the 91 octane and you will be pulling ignition timing with regular. If it is premium required you have no choice, and your a engine can knock even with knock sensors under certain conditions. As for ethanol content, it depends on the vehicle. Cars are still designed to run 100% gasoline because of economy testing. They are however becoming more and more immune to showing any differences. A bunch of years ago when 100% gasoline was still available in Michigan, I had a 93 Passat with a VR6. That thing ran like crap on E10. I replaced it with a 07 Impreza, and that didn’t have any performance differences that you could feel, but did have worse fuel economy. When I lived in Washington state, there were a few stations that had 100% gasoline. I ran it in my 13 Miata for a couple of fill ups, and could never perceive a difference. It’s probably like this with most vehicles built this decade.

  • avatar
    arach

    The other thing to consider is how often you drive.

    I rarely get through a tank of gas in a month, and sometimes I can take 2-3 months. I notice with ethanol in the tank, after about 2 months I sometimes get puffs of smoke out of the exhaust of any car, probably because of water absorption into the gas.

    The pure gas has a lower risk of water absorption. Therefore I much prefer to put that into my vehicles I drive only rarely (once every few weeks).

    • 0 avatar
      FormerFF

      That’s the big determinant. We use 90 octane E0 in our boat for that reason. All cars built in the last decades have no problem with E10, but if your car sits a lot, you’re better off without the ethanol.

      I have a plug in hybrid, it has a pressurized fuel system to keep condensation out. Good thing, I can go two or three months on a tank.

      • 0 avatar
        millmech

        Pressurized fuel system, including the tank?

        Isn’t that more dangerous than usual?

        Isn’t all the fuel just trying to get out & get fire set to it?

      • 0 avatar
        Fletch8

        If ethanol caused problems with water, every single winter there would be millions upon millions of stalled cars throughout the upper US and especially Canada with frozen fuel lines. It is the exact opposite today, we do not freeze fuel lines and don’t need HEET or DRYGAS because we already have alcohol in our gasoline.

        The fact is there were problems with water when E0 was the only fuel around and little cans of alcohol called HEET and DRY GAS(gasline antifreeze) fixed them.

        Today E10 has no water problems and Mercury Marine also said E10 may be the superior fuel(over E0) because it keeps the fuel “dry” in a webinar.

        Water separates from straight gasoline, not ethanol blends.

        According to a paper published by the Society of Automotive Engineers, at 68 degrees F, alcohol with as much as 45% water will mix with gasoline and not separate. With 4%, alcohol will form a stable mix with gas down to about minus 22 degree F.*

        *A.C. Castro, C.H. Koster, and E.K. Franleck, Flexible Ethanol Otto Engine Management System 942400(Warrendale, PA:Society of Automotive Engineers International, 1994)

        …Mercury Marine, which recently hosted a Webinar on ethanol myths, noted that ethanol does not “grab water molecules out of the air.” It is hydrophilic, which means ethanol holds water. With regular gasoline (E0) as well at E10, the primary cause of water collecting in tanks is condensation on tank walls. But unlike E0, which can absorb almost no moisture, E10 can hold up to half of one percent of water by volume, and the water molecules will dissolve in the fuel. The “solubilized” water will bypass the water separator and burn harmlessly through the engine…

        The DOE tested ethanol blends vs straight gasoline and found ethanol blends store three times longer.

        https://www.theautochannel.com/news/2016/09/22/286340-new-government-lab-research-confirms-ethanol-blend-fuels-are-better.html

    • 0 avatar
      Featherston

      That’s a good point, arach. If I recall, the first-gen Chevy Volt had either a requirement or recommendation for premium fuel for precisely that reason. In the spirit of “do what the marketing execs and the consumers want, even if it’s the wrong thing,” the second-gen Volt calls for regular. (An actual Volt owner might confirm or deny this; I just remember reading it when the 2nd-gen was coming out.)

      Another factoid: If the driver’s use pattern skews toward 100% electric, the Volt will use the gasoline engine periodically in the interest of cycling out old gas. Kind of cool, if you ask me.

      • 0 avatar
        FormerFF

        I have a Fusion plugin, it does the same thing with the gasoline, if you don’t use it all up over a long time, it will start running the engine. I’ve never had that happen.

        It also will go into an oil maintenance mode if you make too many short trips using the engine, especially in cold weather, where it runs the engine continuously for about 20 minutes so that the oil gets hot enough to evaporate the moisture that’s built up. I have experienced that a few times during the winter months.

      • 0 avatar
        Blackcloud_9

        Yes, the 1st gen Volt required premium
        2nd gen does not because it is a totally different engine.

  • avatar
    TR4

    The hp difference is about 2% which you will not notice in normal driving. This 8hp difference only applies at 6300rpm and wide open throttle; how much time do you spend there?

    The pure 87 is 9% more expensive than the gasohol but the fuel economy will only be 3% better. From a practical and economic perspective the 87 gasohol is the best choice.

  • avatar
    redapple

    Iowa is the corn state.
    The corn lobby (and Archer Daniels Midland and Cargill) jammed this ethanol crap on us.
    Like the author said. Oh the irony. In Iowa they can get E-0 CHEAP!!
    I live on a lake in North Georgia. We boaters are quite vocal about having E-0. Outside of the lake area, it is not easy to find. Around the lake is is common. The upgrade to E-0 is almost ONE F—ING DOLLAR.
    Nice. The ones that jammed it down our throat dont suffer.

    • 0 avatar
      Ubermensch

      You can thank our POS Senator Chuck Grassley who is all against handouts.
      Unless it is for the ag industry, then there isn’t a handout he doesn’t like. He is the walking embodiment for idea of term limits.

      • 0 avatar
        FreedMike

        This. Grassley was in office when I was a freshman at Drake – in *****1981*****.

        Then again, how many times did Teddy Kennedy, Robert Byrd or Strom Thurmond get sent back to Washington?

        WTF indeed.

      • 0 avatar
        thelaine

        Grassley cannot do it by himself. You vote for my handout and I vote for yours. Ethanol was sold as clean, green energy and energy independence, while helping our all-American family farmers right here in our heartland. Win, Win, Win! The Ruggles of the world loved the idea. Instead, it is just graft. ADM gets a vig off of every gallon sold and senators get a kickback. Chuck stands tall and drivers bend over.

        Think about that the next time someone argues for their favorite subsidy/mandate because, after all, everybody else gets one and MINE does something REALLY important. After all, didn’t the government invent the internet? Unfortunately, it is waste and graft all the way down. Eventually, our debt will be as much as our GDP. Oops, it already happened.

        “The Government Accountability Office not long ago counted 345 different federal initiatives supporting solar energy. The programs are managed by nearly 20 agencies and support more than 1,500 individual projects. Over the past five years alone, the federal government spent $150 billion on solar energy and other renewable energy projects. Preferable tax treatment given to solar and other alternative electricity initiatives cost Americans nearly $9 billion annually, according to the IRS. Billions of dollars have been blown on solar boondoggles—Solyndra being just one of them—and more boondoggles are in the pipeline (so to speak), since nothing encourages the venture capitalists at the Department of Energy like failure.”

        http://www.forbes.com/sites/realspin/2015/02/25/solar-energy-delivers-too-little-bang-for-billions-invested/#18504a8f49f3

        Good article. Worth a read.

        • 0 avatar
          FreedMike

          And with this, thelaine’s Anti Solar Jihad continues.

          • 0 avatar
            thelaine

            I LOVE solar. You missed the point entirely, as you habitually do.

          • 0 avatar
            thelaine

            “There is only one power source, and it’s name is Hydrocarbon.”

            Meh, doesn’t sound awful, FM. Maybe you have a point.

            Solar is fine. Let it sell itself where it can. In limited applications, it is the best answer.

            It is transfer payments, subsidies, mandates, and giant, wasteful, corrupt government that is bad, FM.

          • 0 avatar
            thelaine

            its

          • 0 avatar
            FreedMike

            “It is transfer payments, subsidies, mandates, and giant, wasteful, corrupt government that is bad, FM.”

            …this message brought to you by the personal computer and the Internet, both developed via transfer payments, subsidies, mandates, and giant, wasteful, corrupt government…tune in next week for the “We Landed Incompetently On The Moon” segment of The Anti-Gubmint Show.

            (If you think solar is a good idea, then the government’s gonna have to subsidize it one way or another. It’s the way new tech gets done here in America.)

          • 0 avatar
            thelaine

            Wrong. Tech did not start with the space program. It exploded with the industrial revolution, which is what made America rich. Mostly, it was private industry. You can point to the space program all you want. It does not justify billions upon billions of dollars of waste. You will point to it over and over again to justify damn near any waste and fraud. Government is necessary, but it should be minimized because it is a threat to your freedom and your prosperity. You think the opposite. I get it.

            “We often hear that government created the internet. It’s funny what a myth that is, that government had anything to do with creating the technological revolution. Now the real story is that when government was really involved in dominating the technological sector back in the 1950s, it wasn’t really producing anything for the American economy. It’s when government decided to get a little smaller through the tax rate cuts of the 1960s that Silicon Valley took off.

            Going Back to the Start

            Silicon Valley started out making guidance systems for missiles for the Defense Department.
            Let’s go back to the 1950s, when you really start seeing the Valley begin to expand under Frederick Terman. You start to see lots of new companies coming in there. What we would call startups today – but they didn’t call them that then – of engineers came to San Jose, California to start making things. Virtually all of these people were paid under government contracts – for example, Shockley Semiconductor, easily the most famous and important Silicon Valley company in the 1950s. They were mainly interested in producing guidance systems for the missile arrangements of the Defense Department and all sorts of government contracts.

            What you don’t see in the 1950s and the early 1960s in Silicon Valley is the development of personal products that are technological products that are broadly useful to the American economy at large. You don’t see the personal computer revolution, all sorts of devices, all sorts of applications that people in the private sector can use. It almost exclusively is a phenomenon of government contracting.

            1964

            Well, what happens in the mid-1960s? There’s a big tax cut. The tax rates go down at the top from 91 percent to 70 percent, and at the bottom from 20 percent to 14 percent, and, across the board, a 30 percent tax cut comes in 1964.

            Do you know what else happens in 1964? The term “venture capital” is essentially coined. What does venture capital mean? Venture capital is when an investor decides to give a first investment to a guy with a really good idea that’s completely untested. The term hadn’t existed before then, but explodes in usage beginning in 1964.

            The term “venture capital” was invented the same year major tax cuts were instituted.
            Why? Well, when you have high tax rates, first of all, rich people don’t get to keep a lot of their marginal incomes. They aren’t able to accumulate the venture capital. Then, second, if this idea takes off and starts to make a lot of money, you don’t want the government to take all the proceeds in terms of the tax code. You want the tax code to take it easy with the amount of money the firm makes. So it’s funny, right then in 1964, you see the explosion in the use of the term “venture capital” just as the tax cut comes in.

            And that’s when you see the transformation of Silicon Valley. People who have left Shockley Semiconductor, most famously Gordon Moore and Robert Noyce, start to think about how we can have more broadly marketable technological products. These two guys, with a few others, go on to found Intel in 1968, which then enables the personal computer revolution.

            They said, “We’re going to kind of move away from making guidance systems for the Polaris missile. What we’re going to do is embed computer chips into personal devices that can put computers on the desks of everybody in the United States.”

            https://fee.org/articles/silicon-valley-exists-thanks-to-tax-cuts/

          • 0 avatar
            Arthur Dailey

            @thelaine, you make some excellent points, however you do not mention the major factor that drove most innovation, war.

            The Industrial Revolution did not make America ‘rich’ it was WWI when the USA sold armaments, foodstuffs etc to the Allied countries and made sure that they paid for them in cold, hard cash. Great Britain which was still the dominant economic power at the time had to sell off their investments in the American markets, railroads, etc to pay for their war.

            Aircraft went from unarmed ‘pusher’ types to multi engine bombers in a period of 3 years.

            In WWII, rockets, jet aircraft, etc were designed, tested and put into production in a matter of 5 years.

            And America once again profited, as all of their economic competitors to all intents has their infrastructure destroyed.

            As to venture capital and taxes, the ‘trickle down theory’ has been proven multiple times to be not only incorrect but something of a ‘hoax’. Laffer was more interested in politics than economics. His key backers originally were Dick Cheney and Donald Rumsfeld.

            And just how well have Laffer’s theories worked in Kansas????

          • 0 avatar
            FreedMike

            I didn’t say tech start with the space program. That’s you putting words in my mouth.

            No doubt all of this would have been developed eventually. But with all that “government waste,” it got developed far more quickly, and more importantly, *it all got developed here.* OUR country is far wealthier as a result.

            You can try to disprove that if you want, but good luck.

            Things like solar power and electric cars have the potential to be sold A LOT, at a very high profit. Thus, we subsidize them. Or should we let the “free market” – which is now worldwide – work its’ will, and have India or China develop this tech, and reap the economic benefits? Your call.

    • 0 avatar
      FormerFF

      I live in north metro Atlanta, and am seeing 90 octane E0 at a few stations near my home. It sells for about 15 cents more that 89 octane E10.

      It’s about a dollar more at the marina. I don’t begrudge them that dollar, having to maintain a floating fuel dock isn’t cheap, and it’s only busy five months out of the year.

      • 0 avatar
        redapple

        No. $1 more at Gas stations near the marina.

        Where do you get E-0 so cheap???? I ve never seen it in GA.

        • 0 avatar
          FormerFF

          I filled up my Fusion with 90 octane E0 last week in Norcross at the Shell station on the corner of Holcomb Bridge and Spalding, it was $2.69 per gallon, while E10 87 octane was $2.24. There’s a QuikTrip that has E0 not far from my house, on highway 92, west of Roswell, just in east Cherokee county, that has E0.

          Racetrac has four locations in Georgia, you can see them on their store locator page.

          There’s a Valero station just east of Highway 400 on Georgia 369 that also has it.

    • 0 avatar
      FormerFF

      Where I am the difference between 89 octane E10 and 90 octane E0 is about 15 cents. It’s much more expensive at the marina because it’s at a marina, not because it’s E0.

    • 0 avatar

      @redapple: perhaps you meant E-10 cheap. E-0 is more expensive – usually about 20 cents higher in cost per gallon.

  • avatar
    John R

    Me when I saw the jpeg for ethanol free gasoline – goo.gl/FvFCyh

  • avatar
    FreedMike

    A couple of weeks ago, I began putting 91 octane (which I believe has ethanol here in Colorado) in my ’17 Jetta 1.4 TSI. Throttle response is noticeably better with the more expensive gas, particularly when the A/C’s on.

    I tried 91 octane in my ’03 Buick with the 3800, and didn’t notice much of a difference at all.

    Might be worth a few extra bucks a month.

    • 0 avatar
      notapreppie

      Throttle response on a modern turbo car is largely dictated by turbo spool state and DBW throttle position mapping.

      If I were a betting man, I’d bet that you wouldn’t actually be able to tell the difference in a properly blinded study.

      • 0 avatar
        FreedMike

        I’m no tech-head, so I’ll take your word for it. But on my car, the turbo doesn’t really kick in until around 2000 rpm, give or take (it depends on what gear you’re in, how many passengers you have, etc). After that, it’s all good.

        But from idle to around 2000 rpm, the 1.4 is fairly laggy – after all, this is a 3200 pound car with a tiny engine. Without the turbo, this car is radically underpowered, particularly when the A/C’s on, and there’s a “slogging” feeling from the engine when you try to accelerate from 40-50 mph in a higher gear. You also get the same sensation on the freeway around 65 mph, when you try to accelerate in fifth. This is where I see the improvement with better gas. Throttle response in this situation is noticeably crisper and more progressive.

  • avatar
    Land Ark

    I just spent a used 2000 Honda Civic amount of money replacing the fuel system in the Land Ark (my 1967 Impala for those who don’t know). I replaced the tank, sender, fuel pump, and all the fuel lines. I specifically went with lines that would be compatible with ethanol fuel because that’s the only choice for gas I have out here and I am worried we’ll be seeing E15 soon.
    Of course, as I have said in the past, the car was running fine on E10 for the last 20 or so years, but my fuel gauge was broken and the tank was original and possibly leaking so while I was at it I went ahead and did everything.
    It has been an utter nightmare since. First the sender popped out while I was pumping gas right after it was done and I spilled 2 gallons of gas all over the station. Then my garage was constantly filled with fumes and I couldn’t figure out why. I’ve since pulled the tank again and I think solved that. And now it won’t start. So, to anyone out there worried about ethanol and has a working car, just keep going until it actually is a problem.

    I have said it before, I hate that they add ethanol to gas. We should not add things to gas because of lobbying. With that said, I found a station that had straight gas and did an MPG experiment in my Tacoma. After two tanks of each I saw 2 MPG higher in similar driving conditions with E10 than I did with straight gas. Those results annoyed me greatly.

    • 0 avatar
      redapple

      Agreed
      I swear I got 2 mpg improvement in my accord v 6 with E-0.

      • 0 avatar
        285exp

        Independent labs have done controlled testing showing that fuel efficiency changes in proportion to the change in energy content in the fuel, so since E10 has around 3% less energy content than E0, that’s about what the decrease is going to be. That has been my experience as well. Land Ark doesn’t specify what mpg he was getting prior to his Tacoma E0 experiment, but 2 mpg seems an awful lot for a truck rated around 20 combined, and just because his driving conditions were “similar”, it doesn’t mean that any difference in his fuel economy for a couple of tanks was due solely to the ethanol content in the fuel. Same thing with a 2 mpg difference in a V6 Accord, you don’t say what it was using E10, but you can’t say for certain how much of any change in your mpg was due solely to the amount of ethanol. Regardless, unless the % increase in mpg is greater than the % increase in cost, burning E0 is just a waste of money unless you’re driving an antique vehicle that doesn’t have an ethanol resistant fuel system.

        • 0 avatar
          Scoutdude

          No labs have not found that the mpg is directly proportional to the BTU content of the fuel.

          The test I read used about 10 cars that included a mix of standard and FFV versions. They found great differences in the MPG using the EPA designated methods. In that test at the one end you had the Camry that had a negligible drop in MPG, less than 1%, and at the other end a non-FFV Fusion lost ~10%.

          Yes the energy content does play a factor in MPG however the rate at which the fuel burns and the ignition timing also play a factor. Ethanol has a slower flame propagation rate than gasoline so when you add ethanol and don’t change the timing you are wasting energy out of the tail pipe because peak cylinder pressure did not occur at the optimal time.

          The same test also went beyond E10 and kept testing with ever increasing amounts of ethanol. For non FFVs they stopped the test when an adaptive fuel limit reached code was obtained and for the FFVs all the way to E85.

          On the Ford and GM FFVs a strange thing happened as the ethanol percentage increased. The result was not a straight line, far from it. The curve actually showed it staying close to flat from E0-E10, then dropping E10-E30 The curve then took a turn and increased with a local peak at or near that E10 level at E40 or E50 depending on the exact vehicle. The MPG then dropped off dramatically from E60-E85.

          So no BTU’s are not the only factor in MPG.

          • 0 avatar
            285exp

            “No labs have found that the mpg is directly proportional to the BTU content of the fuel”

            All 13 vehicles exhibited a loss in fuel economy commensurate with the energy density of the fuel.* With E20, the average reduction in fuel economy (i.e., the reduction in miles per gallon) was 7.7 percent compared to E0.

            https://www.afdc.energy.gov/pdfs/int_blends_rpt_1.pdf

          • 0 avatar
            Scoutdude

            Not exactly independent testing there, since it was bought and paid for by the DOE to further their agenda. You’ll also note that regarding fuel economy they only give you the data for the average, not how it affected individual vehicles.

          • 0 avatar
            Scoutdude

            Well I did find graphs that report the MPG in the most obscured way that they could, with a poorly scaled graph, just so they could fit it in with the emissions.

            However that data supports what I’ve been saying that the MPG does not track ethanol percentage. Take a look at the Altima, on E15 it does better than it did on E10 and is near the E0 number, but due to the graph it is hard to say exactly.

            The 03 LeSabre’s and 07 Silverado’s graphs also do not follow that the MPG difference linearly equates to E%. The drop from E10 to E15 is definitely less than the drop from E15 to E20.

            The 03 Taurus also shows that the FE is not in direct proportion to E% as its E15 and E 20 numbers appear to be the same.

            The 99 Civic appears to be essentially flat from E10-E20 and the Camrys are also pretty low slope.

            So how exactly does that study prove that the MPG is directly proportional to the BTU content of the fuel?

            Yes as E% rises the MPG trend is downward but the slope is not consistent from vehicle to vehicle and for the majority of them it is a curve not a straight line.

            If the MPG was only dependent on the energy content measured in BTU’s then we would see a line with a consistent slope across all of the vehicles, or at the very minimum a consistent curve.

          • 0 avatar
            285exp

            Scoutdude, it’s kind of hard to address the test you’re talking about if you don’t provide a link to it.

          • 0 avatar
            285exp

            I’m sorry Scoutdude, I see now you were referring to the test I linked to. You can quibble about the vehicles not all showing an exactly linear relationship between the amount of ethanol and mpg, but the great majority of them do, and you have to remember that these are not flex fuel vehicles, so they are not optimized for using blends greater than E10. Anyway, none of the variations you are pointing out are very large, and I think the executive summary of the report reflects accurately the overall results.

            If you can find another test that shows something different, I’ll be happy to reconsider.

          • 0 avatar
            Fletch8

            Oak Ridge National Laboratories measured mileage of E85 vs E0 with power taken into account, called the gasoline equivalent ratio and found E85 in the US flex fuel fleet averages 3% better mileage when horsepower is taken into account. They do graph the ranges of the vehicles.

            See bottom of page 7 top of 8 here:
            http://web.archive.org/web/20170121004456/https://www1.eere.energy.gov/bioenergy/pdfs/analysis_saab2007.pdf

        • 0 avatar
          Land Ark

          It’s important to note that I am not a scientist and, no, my test had absolutely no value other than to frustrate me. I was hoping to see worse mileage with the E10 so I could strut it around complaining about how E10 is ruining mileage.
          Similar conditions yet not the same, at the time I was doing about 85% highway driving on my daily commute and it’s a 50 mile rural highway trip to the E-free station.

          • 0 avatar
            285exp

            Scoutdude, if you had actually read the article instead of just dismissing it because of your perceived bias, you’d see that they did report individual results, not just the average. They describe the testing in some detail, so you might try telling us why you think the results don’t mean what they say they do instead of just calling ORNL paid shills for the feds. You could also link to some tests that refute their results. You said there were no tests showing that mpg changed in proportion to the energy content of the fuel, I provided one that did, you’re up.

  • avatar
    redapple

    Add 10% ethanol and get 7% decline in the MPG. Nice. That makes sense.
    (Anybody know if the EPA still MUST us E-0 in MPG testing???)

    What about all the energy used in making the ethanol.??

    Dont get me going on the increased food pricing. Since food is more expensive, 3rd world folks buy less and Starvation DEATHS increase.

    • 0 avatar
      notapreppie

      It should be closer to 3%.

      That said, I agree with you that burning food is conceptually a bad idea.

      Ethanol is a really good replacement for MTBE but we should find another way to make it if we want to use it to offset our fossil fuel addiction.

    • 0 avatar
      brn

      Straight from the EPA: https://www.fueleconomy.gov/feg/ethanol.shtml
      “Ethanol contains about one-third less energy than gasoline. So, vehicles will typically go 3% to 4% fewer miles per gallon on E10 and 4% to 5% fewer on E15 than on 100% gasoline.”

      As far as food, that’s an old wives tale. Ethanol is made from feed corn, not sweet corn. The by-product of producing Ethanol is animal feed. If you take both into account, Ethanol production is a much better use of resources than gasoline production.

  • avatar
    Flipper35

    If the price difference is around 3% or less I always go for the straight gas. Especially in the winter. It sucks having a fuel pump replaced because the ethanol turns to gel when it gets condensation and plugs the filter on the pump. I was happy that it was covered by the warranty.

    The energy used to make ethanol has been a wash or better since over 10 years ago.

    • 0 avatar
      notapreppie

      FYI, ethanol + water does not equal gel. Something else is going on in the fuel system if that is happening.

      • 0 avatar
        Flipper35

        I was told the ethanol had gelled because of moisture and the service manager is one of the best in the area so I believed him.

        After reading your comment I looked it up. It does appear that water will cause phase separation and that can allow the ethanol to coagulate. Especially if there are hydrocolloids. On the marine boards there are lots of explanations similar to this:

        “Ethanol has an electric charge that attracts other polar molecules. Water sucks right into the fuel. Because water is heavier than gasoline, it collects at the bottom of the tank and turns into a gel. At about 0.5 percent water, this is called phase separation, and then that phase coagulates in cold weather.”

        • 0 avatar
          notapreppie

          Well, you’re welcome to believe him but I’m a chemist and have used ethanol with and without water as a solvent and reagent.

          If ethanol + water = gel then why is every alcoholic beverage from 0 – 200 proof sill a liquid?

          Ethanol doesn’t have an electric charge but it is fairly polar and so is water (which is why they mix well). Ethanol (and most alcohols) have lower melting points than water, as well, which is why products like HEET work. It lowers the melting point of the water, causing it to melt and get pulled through the fuel line into the engine.

          Water is more dense than gasoline and doesn’t mix with it well. Ethanol and isopropanol (rubbing alcohol) mix with both very well which means that adding those to the gasoline mix will actually help the water dissolve into the gasoline (assuming the alcohol isn’t already saturated with water). This will actually have the effect of drying out the gas tank slowly over time as you repeatedly fill and empty the gas tank.

        • 0 avatar
          Scoutdude

          You need more than .5% water to cause phase separation.

          Ethanol is hyrgosopic so yes in high humidity conditions it will absorb water out of the air. However it takes a well ventilated storage container and a lot of temp swings to get to the point where there is a problem. In a sealed container or with a tightly regulated ventilation system as has been used in automobiles for decades it is a non issue.

  • avatar
    mikey

    According to Ford, my EB Mustang will run just fine on 87 octane 15 percent ethanol. In my experience the Mustang runs better, has more power, and delivers improved milage with 91 or better.

    I own a Toro Lawn Mower and snowblower , and a Stihl Trimmer, and Leaf Blower…The dealer tells me “Don’t even think about running 87 Octane in any of them”

    I don’t remember the last time I bought 87 Octane

    • 0 avatar
      FreedMike

      Same deal in my 1.4T Jetta. I don’t notice much of a difference when the motor’s “on the boost,” but I definitely do in situations when the turbo isn’t spinning much (i.e., slogging around at low speeds with the A/C on, running 45-50 mph in fifth in traffic, trying to pass on the freeway without downshifting, etc.).

    • 0 avatar
      bumpy ii

      I run 87 E0 in my weedwhacker, since I figure that’s better than letting E10 sit in it for a month or two. I have replaced one carb on it already, and when the next one dies I’ll use that as an excuse to get a battery-powered whacker.

    • 0 avatar
      brn

      My Toro lawn mower and Arins snow blower both run E15, 87 octane. The key is to not let gas sit in them for months on end. I drain both at the end of their relative seasons. I always keep seafoam in the snowblower, as I don’t know how long it’s going to go without running.

      Ever since I started doing the above, E15 hasn’t been an issue. Before I used to let the gas sit in them off season and that resulted in my having to clean the carburetors after a couple of years.

      Btw: When whacking your weeds, battery is the only way to go.

  • avatar
    PrincipalDan

    I’m in Sajeev’s boat in this case.

    No E0 gasoline within 130 miles of me but their is a refinery within 30 miles of me.

  • avatar

    The New York Metro Area is an ethanol only zone, with claims of less pollution. The nearest e0 pump is about 70 miles north, in Ulster County, at a Stewarts’ (yes, I know where it is-and you can find it by the line of motorcycles in front of it).

    For your typical car guy who burns a tank a week, I don’t think it makes any difference. Toys, however, are another story. You only need a tiny amount of water to destroy the ethanol fuel, and this is compounded by anything that won’t see constant use. Think boat, cycle, jetski, or on the other side of life, lawnmowers, chainsaws, or weed whackers.

    You’ll get separated fuel and a brown gunk, which clogs the fuel system. We had one jetski trip ruined by ethanol (which usually helps the post ride part, :) ) when ethanol first came out….

    I now try, where possible, to keep a 5 gal jug in the trunk when I’m’ going north. At the least, I store my gadgets with fuel stabilizer, or the E0 if I can get it before winter.

    I’ve said it before, but will end it again….ethanol is for drinking, NOT driving……

    If you want a giggle, go to the ADM website and follow links to beverage alcohol. I was in a college area liquor store and was amazed at all the brands of cheap vodka….and wondered where they all came from….

    • 0 avatar
      brn

      See my post above on how I safely use E15 in toys.

    • 0 avatar
      Iowa

      The irony of ethanol production is it diverts feed corn from the food supply and, therefore, increases the price of food. Production of ethanol also is notorious for polluting streams. It also is requires the energy of a industrial plant to produce it.

      How, again, is this an “alternative” energy?

      • 0 avatar
        brn

        “The irony of ethanol production is it diverts feed corn from the food supply”

        An incomplete and misguided statement. A by-product of ethanol production is animal feed, healthier than strait feed corn. It’s an excellent example of fully utilizing a resource.

  • avatar
    TR4

    So one guy gets 2mpg better with E10 and another gets 7% worse? I’ll believe the scientific fact that E10 has 3% less energy than E0.

    • 0 avatar
      MBella

      It depends on the vehicle and its calibration. If you have an reasonably priced ethanol free option near you, it might be worth it to try it in a few tanks, and see how your vehicle reacts.

    • 0 avatar
      Ubermensch

      There is less energy but the alcohol gives a charge cooling boost so you can get a little more power if your engine is tuned properly to take advantage of it.

      • 0 avatar
        Scoutdude

        Actually you can make more power simply because a gallon of ethanol needs less air to completely burn and since getting air in and out of the engine is the problem you can get enough extra fuel in there to more than make up for the lower energy density.

  • avatar
    raph

    You can check a GGE table to see the difference in energy content which is pretty neat.

    Anyways

    IMO if it comes down to simply stretching your dollar then check the fuel economy for each type of fuel. The regular gasoline packs more BTU per unit and also isn’t an oxygenated fuel like E10 or what have you so it should require less fuel to produce the same or better power – on the other hand your changing ignition timing in an effort to alter dynamic compression due to the increased volatility of the fuel and in doing so your leaving some fuel economy on the table since firing at a lower compression isn’t as efficient and if the difference in average power is enough you’ll try and compensate with a set of extra leaded shoes.

    I ran into that when I stepped out of the GT500 which produced about 630 hp at the rear wheels on a hot day to about 460-470 in the GT350 in the same conditions. Subconsciously I expected the GT350 to pull like the GT500 so I exagerated throttle input until I could get about the same feel in acceleration with predictable results in economy.

    Ultimately you have to see how it balances out in day to day driving and see how the economy goes.

  • avatar
    Scoutdude

    The fact is that the MPG drop caused by using lower octane in a vehicle that recommends premium varies from engine family to engine family. The effect of E10 on MPG also varies depending on the engine.

    So the only way to find out how it works out for your car is to test it yourself.

    Run a couple of tanks of each in your regular day to day driving then compare those results with the price. Also compare the seat of the pants dyno results if that matters. If you don’t notice, or don’t care about any lost performance then use the fuel with the lowest cost per mile.


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