By on April 10, 2014

Octane

Should United States gasoline octane standards be updated to match those in Europe, fuel efficiency could see a significant improvement, along with increases in engine power.

Ward’s Auto reports the Detroit Three powertrain bosses laid-out their case for increasing octane ratings before attendees at this year’s SAE World Congress. In short, by matching ratings with those in Europe — where the highest rating is 95+ — engineers could build engines for higher compression, leading to increases in fuel efficiency and power instead of the losses in both found in engines made for the U.S. market, where the highest rating available is 91.

The idea has precedent, as diesel fuel was brought in line with European standards seven years ago, with improvements to both engines and emissions as a result.

Though the Detroit Three bosses brought the issue up with the Department of Energy and various power players within the Beltway, only now have they brought it before the public, as Ford chief Bob Fascetti explains:

I can’t say we’ve actually lobbied together, but it’s a common-sense thing. If we had a single-octane fuel that was higher, then we can take advantage of that for the customer, we can implement higher compression ratios and we won’t be knock-limited on the fuel. It’s win-win for the innovators as well as for the customers.

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83 Comments on “European-Style Octane Could Boost Efficiency, Power In US Engines...”


  • avatar
    mike89

    In Europe, 95 is the lowest octane rating, not the highest.

    • 0 avatar
      Drzhivago138

      European octane ratings are also different than US.

    • 0 avatar
      grassharp

      Not entirely true, in Germany you can also find 91 octane ‘normal Benzin’. I suppose you will find that in more countries.

      • 0 avatar
        felix

        Agree. And 91 in Germany (RON scale) would be equivalent to 86 octane in the US (AKI scale)

        • 0 avatar
          Onus

          Russia also has 91. They even had like 70 something. But, that is long gone with sulfur limits reduced.

          I think they are starting to phase out 91 as well.

          • 0 avatar

            As far as I recall in Russia octane ratings are (or were) 92, 95 and 98. Russian cars run on 92. When I bought Toyota I switched to 95 and there was no other way to run (Euro) midsize Toyota with 1.6L engine. With 92 it would hardly move. Russian cars suck no matter what. That’s the problem with Euro cars – they are heavy and have tiny engines.

    • 0 avatar
      Johannes Dutch

      Correct, “Euro 95″ is the most common gasoline. That’s octane rating 95 RON (around 90 AKI). It contains up to max. 5% bio-ethanol.

      Highest rating I can get here, for my 1969 Plymouth with a 340 engine, is BP Ultimate 98. So that’s 98 RON (around 93 AKI) and it’s ethanol-free.

      Not sure, but I believe that 102 RON is available as pump gas in Germany. A few years ago they tried E10 fuel there. Big failure, the Germans simply refused to put it in their cars. Nobody bought it, literally.

  • avatar
    Manic

    Please don’t forget RON/AKI! Different octane measurement systems. Euro 95 = US 91 approx. Does that mean that D3 wants to move all cars to US 91 octane and some to US 94 AKI?
    http://en.wikipedia.org/wiki/Octane_rating#Regional_variations

    • 0 avatar
      Onus

      What he said ^

    • 0 avatar
      Lorenzo

      Well, before AKI, Ron 95, currently about AKI 91, was regular. The conversion to AKI seems to have given us lower octane ratings, maybe because engine anti-knock systems really work. I’d like to see ratings based on BTUs, so we know how much energy we’re getting for the buck.

      • 0 avatar
        DC Bruce

        Yes, but the point is, engine anti-knock systems work by retarding spark timing, which reduces efficiency. Higher compression engines, as a rule, are more efficient; but the limiting factor in increasing compression is engine knock. Higher octane, which inhibits knocking, would allow engines to operate at higher compression and therefore more efficiently. That’s one of the benefits of DI. Since spraying the fuel directly into the combustion chamber has a cooling effect (reducing knock tendency) higher compression ratios can be used without requiring higher octane fuel.

        • 0 avatar
          stuki

          In the picture above, there is a 14% increase in price between 87 and 94 Octane. I seriously doubt the increased efficiency from designing an engine exclusively for 94 would add up for the end user. While leaving his engine less versatile. Imagine needing to drag along booster to take a road trip to Mexico….

          In Europe, efficiency has taken on the trappings of a religion. It’s gone way past rational design.

  • avatar
    28-Cars-Later

    Does Euro gas have 10% ethanol?

    • 0 avatar
      SteelyMoose

      This. Get the corn squeezin’s out of the gas (aka taxpayer free lunch for ADM) and we’d see a mileage increase with existing engines.

      • 0 avatar
        PrincipalDan

        As one of Jack’s female fiends said when riding in his flex fuel capable Town Car: “If the car runs on alcohol, what are we going to drink?”

        But seriously, even having been born and raised in farm country I think Ethanol is a silly attempt at a solution to a problem. Especially since car companies get extra credit for every flex fuel vehicle they sell.

  • avatar
    peekay

    In Canada we have 87, 89, 91/92 and some brands have 94. My 2008 Porsche is labelled with 93 as recommended, as are a lot of European cars I believe. Sure it can run on 91 when I drive in the US, but here at home I use 94 and there is a noticeable difference.

    Oh and the 94 octane Chevron gas in BC is the only grade with zero ethanol, so that helps performance and fuel economy.

    • 0 avatar
      Brian P

      This varies regionally. Here in Ontario, PetroCanada has 94, but it is loaded with ethanol. Shell V-power 91 is the only one advertised as having no ethanol.

      • 0 avatar
        davefromcalgary

        Myself and anyone I know with DI engines will only use Shell V-Power or PetroCanada 91 as a minimum. Partly for knock resistance, but also for those brands being top tier detergency fuels, to prevent gunk buildup.

        • 0 avatar
          th009

          Petro-Canada mixes in ethanol into the premium blend, at least in Ontario, while Shell and Esso do not. So I prefer either Shell or Esso for my engine …

          • 0 avatar
            davefromcalgary

            I’ll have to check the pumps, as my new car came with a 40c/L off card, so ill be gassing up at Petro for a while.

            I know my mom and bro have VW products that require premium, and they actually recommend Petro and Shell based on detergency standards.

          • 0 avatar
            Pch101

            The ethanol in E10 acts as a detergent. It’s actually beneficial for most modern cars.

            One of the requirements of “Top Tier” gas is that it contains 10% ethanol. For whatever reason, internet car fans don’t seem to be able to grasp that a little ethanol can be a good thing, although you certainly wouldn’t want to use too much of it.

          • 0 avatar
            th009

            I’m happy not to grasp that, I’m not convinced that ethanol has any unique detergent qualities (unless you’re buying cheap fuel that has no other detergents), especially any that require it at a 10% mix.

            On the other hand, it’s a waste of money (subsidies), raises food prices and reduces fuel energy content. No thanks.

          • 0 avatar
            highdesertcat

            th009, biggest problem I have noticed with ethanol-spiked fuel is that the mixture eats through rubber fuel hoses and seals of older cars, not specifically designed to tolerate ethanol.

            In the Great Southwest of America, the arid climate allows people to enjoy their cars longer because of the lack of rust. The leaking fuel lines and oozing carburetor seals because of the ethanol have contributed to vehicle fires.

            The state government is aware of this but is going to pass legislation that will mandate 15% ethanol as soon as they can get the votes together to pass it. Clearly this will be for the benefit of the farmers.

            So I’m afraid we’re in for an even rougher time as we’re forced to use E-15 in our old cars.

          • 0 avatar
            davefromcalgary

            Yup, I filled up at the PetroCanada around the corner today, and the pump looks just like the one in the picture above.

            Since the salesman “couldn’t guarantee the factory put premium in” I decided to put the 94 in this time, but I intend to use 91 regularly.

    • 0 avatar
      JuniperBug

      The previous owner of my car insisted that the car needed at least 89 Octane. That seemed dubious, so I looked in the owner’s manual; sure enough 89 Octane is specified, but 89 RON. Translation: 87 AKI fits that requirement fine. This is also on a Canada-spec car. Be sure you’re comparing the same measuring system on your Porsche.

  • avatar
    Onus

    Diesel isn’t even close to Euro standards. Sulfur in practice but not in spec 15ppm, everything else no. Our cetane is 40 minimum which is way lower than Europe. We export all our good diesel to Europe.

    93/94 is easy to get around here in CT.

    If manufacturers want to require premium go for it but no one will buy the cars.

    • 0 avatar
      Brian P

      In particular, the US lubricity requirements for diesel fuel are substantially inferior to those in Europe (and Canada). This has been giving fuel injection equipment manufacturers grief, and really the US ought to change this.

      • 0 avatar
        Onus

        I totally agree. I drive a diesel truck and It not abnormal to get bad quality diesel. It’s more of a fact of life. My truck is old so it isn’t bothered too much buy it.

        I try to go to a high volume station which seems to solve many of those problems.

        I’ve also had gelling issues as well in the winter.

    • 0 avatar
      RogerB34

      USA diesel 42 – 45 cetane number with exception of California at 53.
      EU varies 51 – 60 cetane number.
      http://en.wikipedia.org/wiki/Cetane_number
      The article is a puff piece for ethanol.

  • avatar
    psarhjinian

    So, for a story about European octane levels in the US, you use a photo of a Canadian pump?

  • avatar
    APaGttH

    Until the corn lobby is told to stick it, it won’t help all that much with the E10 MPG penalty.

    • 0 avatar
      Drzhivago138

      *Sigh*

      I could say something here, but I don’t need to start a Internet argument, because then nobody wins.

      • 0 avatar
        davefromcalgary

        Could we just throw some puns around instead?

        • 0 avatar
          Drzhivago138

          No. Don’t be corny.

          Disclaimer: I’m from a family of corn growers and OSTENSIBLY a supporter of the corn lobby. The manufacturers who complain are, more often than not, supported by the oil lobby who would hold on to the most outdated tech until we’ve sucked Arabia, Canada, Alaska and the Gulf bone-dry. Any energy that can be produced in the US is immediately preferable to imported energy–bonus points if it’s renewable.

          But if I were president (already an impossibility), I would be unpopular and possibly forced out of office because I would do everything in my power to cut spending and subsidies on everything. Military, farm subsidies, welfare, everything gets cut an equal percentage, so you can’t accuse me of favoritism. (Except maybe education; I’d have to keep that.) Everyone would hate me, and on my final day of office, I’d say, “Hey, look at our deficit. Yeah–you see that? It’s positive. We have MORE money than when we started. And nobody died horribly because they had less money to work with. Are you really sure you want me out of office?”

          • 0 avatar
            davefromcalgary

            All of these corn puns go against the grain.

          • 0 avatar
            MBella

            The problem is that your farm family has to use more energy to produce that gallon of ethanol than it contains. It is a better idea than to just use that energy in your car, and eat the corn they grow.

          • 0 avatar
            Pch101

            Ethanol is energy positive when the food byproducts are included in the BTU count.

          • 0 avatar

            > Ethanol is energy positive when the food byproducts are included in the BTU count.

            The byproducts aren’t really much of food.

            Corn is just a bad crop for fuel and mostly an inefficient payoff to certain states.

      • 0 avatar
        Rasputin

        People with logical arguments can win internet arguments, but nobody wins with ethanol except corn growers.
        - Mileage loses.
        - Power loses.
        - Small engines (mowers, etc.)lose.
        - Foreign sawgrass ethanol producers lose (tariffs).
        - Even Mexicans lose (corn tortilla shortage riots).
        edit – Forgot, most importantly, US Taxpayers lose (subsidies).

        • 0 avatar
          NoGoYo

          Why can’t small engines tolerate E10 87 octane, anyway?

          I live somewhere where I don’t mow my own lawn, so my only experience with small engine power equipment was when our family borrowed a power washer to do some home improvement last summer.

          • 0 avatar
            Drzhivago138

            Something with them being two-stroke, I think? I know it does corrode valves as well, but that’s not the only reason.

          • 0 avatar
            NoGoYo

            Well no, the power washer we had was a 4 stroke…it’s probably something about lubrication, though.

          • 0 avatar
            Lorenzo

            Ethanol is a solvent, so it does a nasty job on rubber and even plastic washers and seals.

    • 0 avatar
      ceipower

      You are so right!

  • avatar
    p___mill

    Unless the bump in efficiency is enough to offset the increase in price then it wont be a win for consumers. In TX we have 93 and it costs about 10% more than 87.

    • 0 avatar
      285exp

      Yep, if the % increase in mpg is not more than the % increase in the price of the fuel, what’s in it for us? I’ve got a car where premium fuel is recommended, but I don’t use it because the difference in performance and efficiency is undetectable. All else being equal, what matters is cost per mile, not mile per gallon.

      I can see how this will benefit the car makers though, because they have to hit increased CAFE standards and can get a cheap bump in efficiency by increasing compression ratios and requiring premium fuel; they don’t care if the increase in mpg is less than the increase in fuel cost, because they’re not paying for it and they get to brag about how many mpg they get.

  • avatar
    gtrslngr

    Todays Theme Pt II

    Gee …. ya means ta tell me higher octane in an ICE would make the motor more efficient [ as well as have more horsepower ] ?

    Golly … again … I’m so very surprised !

    [ Hmmm ... lets see if we can find anymore cases of \' Stating the Obvious \' in todays news to react to ]

  • avatar
    Pch101

    “where the highest rating is 95+”

    I do believe that 98 isn’t uncommon in Europe, also.

    But as someone else mentioned, the US and Canada use the AKI scale to measure octane, while most of the rest of the world uses RON.

    95 RON is about 91 AKI. We already have this stuff right now – 91 is premium grade in much of the US, and midgrade in other areas.

    We also have Americans who whine about European cars that require premium. It costs more to make premium fuel, and not everyone wants to pay the markup.

  • avatar
    npaladin2000

    Actually, the highest octane available here is 93, but it’s not available everywhere. Generally 89 and 91 are available everywhere though, if engineers want to design for higher compression.

    The thing is, they don’t. Recall Mazda, when they brought SkyActiv here, they LOWERED the compression to make it work with our gas, because 87 is so entrenched, people don’t want to buy the more expensive stuff.

    • 0 avatar
      davefromcalgary

      They didn’t lower compression for our gas, they lowered it for our mentality regarding spending on premium fuel. It is my understanding that North American premium is just fine for high compression engines.

      I hope that’s not a super nitpicky comment, but I think its accurate and worth stating.

  • avatar
    MrGreenMan

    Isn’t this also just playing the game between CO2 and NOX emissions?

    An immediate search turns up the Watt Committee on Energy’s working group on acid rain report that explains why areas with “fragile environments” like the rarified air of the New Mexican plateau had 86 or even 85 octane gas: Higher octane, higher compression, leaner burn, more nitrous oxides.

    I feel like I rode this ride before but backwards.

  • avatar
    CJinSD

    You can buy 100 octane at the gas station around the corner from me, but it costs $9 a gallon, which may be the point with this regime.

  • avatar
    thegamper

    In Michigan 93 is available pretty much everywhere 9 out of 10 stations anyway. I previously owned a Mazdaspeed6 that required 93 and only a handful of times pulled into a station that didnt stock it. I currently have a 2014 Mazda6 with skyactive engine. I doubt higher octains will become available anytime soon or become standard this decade, but would suck if they did and I have high compression engine optimized for 87. Got to keep us all upgrading.

  • avatar
    TW5

    Higher octane fuel puts money in the pockets of oil companies, while shifting more CAFE compliance costs from the automobile manufacturers to consumers.

    If manufacturers want more octane, they should work on direct-ethanol injection engines. Engines with a second bank of injectors for ethanol, achieve octane ratings around 100 AKI. The fuel is cheaper for consumers than high-octane gasoline, and the only inconvenience to the consumer is topping-up a small E85 tank at every fuel stop.

    Current ethanol blending techniques achieve substitution of about .7 units of gasoline per 1 unit of ethanol by volume. Ethanol injection displaces about 5 units gasoline per 1 unit ethanol by volume, according to the SAE paper published in 2011. Since gasoline-ethanol dual-fuel engines are optimized for high-octane fuel, they are optimized to run on pure ethanol as well, unlike current flex-fuel vehicles.

    • 0 avatar
      Drzhivago138

      Thank you for sharing. I knew coming in here I’d be the minority position, and it’s good to see someone else who can provide an alternative and actually back it up. (I have my convictions, but I’m not particularly good at defending them, which is why I try to avoid starting arguments.)

    • 0 avatar
      daver277

      Manufacturers hate ethanol because it has much lower BTU content so the engines use more fuel and make their fuel economy look terrible.

      • 0 avatar
        TW5

        It’s true that ethanol has lower energy-density than gasoline, but the bigger problem is that E85′s octane advantage is wasted in flex-fuel engines that are optimized for 87 octane gasoline. If an engine is optimized for dual fuel gas-ethanol injection, it makes better use of high octane fuels, like methanol and butanol. Butanol has energy density more similar to E10, and it can be produced as a carbon neutral biofuel.

        • 0 avatar
          Drzhivago138

          See, it bothers me less that most car enthusiasts are anti-ethanol (because if I let that bother me, I’d have a much harder time here) and more that so many of them seem to be so vehemently opposed to anyone trying to make advances towards running on anything besides pure gasoline.
          I thought the goal here was to promote creative engineering so that we can use less of a nonrenewable resource. You’ve got an engine that gets x MPG and runs perfectly on 93 octane? Great–but what would really be an accomplishment if it could do the same on E85.

  • avatar
    rpol35

    As other posters have mentioned, 93 is pretty much the max. octane in the U.S. and I find it to be very common here in Florida. It’s really not necessary in most recent cars that can compensate for high compression with lower octane fuel, though I find it to be essential in older, less sophisticated engines that have higher compression ratios and no knock sensor/ECM timing control.

    To that point, a GM 3.6 litre, direct injected V6 engine has an 11.5:1 compression ratio and develops 300+ horsepower on 87 octane fuel and that is the recommended octane for that motor. If that will work, it begs the question, “Why to we need higher octane fuel?”

    • 0 avatar
      npaladin2000

      Because higher octane does make it easier to design for higher compression ratios. 11.5 is nothing. Ford’s got a 12:1 compression 2.0L in the Focus. My Mazda3 SkyActiv 2.5L is a 184 HP engine at 13:1 compression. It uses a racing header and customized piston heads to promote proper combustion at that high a compression. In Europe that same setup runs at 14:1 compression because Europe uses higher octane fuel. They can’t get it beyond 13:1 on 87 octane.

  • avatar
    Sky_Render

    I have several issues with this article.

    First of all, octane is measured differently in Europe. So that’s not even an apples-to-apples comparison.

    Secondly, 91 octane is NOT the highest you can get in the US, unless you’re talking California with their CARB-legislated junk fuel or higher altitude places like Salt Lake City, where the lack of oxygen allows the use of lower octane fuels.

    And even beyond that, E85 is right around 100 octane! So don’t say that the lack of high octane is holding car manufacturers back, whenever we’ve already got a high-octane fuel available in the form of E85.

  • avatar
    highdesertcat

    FWIW, I run only Premium High Octane gas in all my vehicles, AC generators, air compressors, lawnmowers, trimmers, edgers, tampers and what not. I keep two 55-gallon drums of gas at home because the nearest gas station to my house is 26 miles away.

    In cars and trucks designed to tolerate lower octane gas it keeps the pinging, knocking and ignition-timing retardation down. And by keeping the retardation down it allows the engine to produce all the power it can.

    The difference between octane levels is real. Sometimes, after having been forced to fill up with a lower octane while traveling, it takes a lot more gas pedal to get the car moving. The next fill up with Premium 91 or higher cures that immediately.

    Best gas in MY area is Chevron, Shell (owned by the same oil co.) and Bradley with its local gas from the Artesia, NM refinery. Where you get your gas matters.

    I travel a lot and have tanked up on the road many times. What we pay for on the road is not always what we get into our gas tank even though it says 90, 91 or 92 octane on the pump.

    Even the most modern, cleanest, best-looking gas stations have been guilty of this fraud. The worst in MY experience was an Amoco gas station in Grand Junction, CO, which sold me a rich mixture of water with a tankful of Premium gas. With 1/4 tank of “gas” left it turned out much of it was water, and the engine ran accordingly.

    Fortunately, we had a couple of bottles of gas-dehydrator with us and that cured the problem allowing the engine to burn the water along with the remaining gasoline.

  • avatar
    Samuel Morse

    Most mainstream cars in Europa have gasoline engines running on 95 NO gasoline, while sport vehicles’s manufacturers do recommend 98 NO gasoline for higher compression engines, usually above 9.5:1.
    Wonder if increasing octane index of US gasolines will lead to manufacturers having to increase their compression ratios of their engines.

  • avatar
    DrGastro997

    It’s about time we get a true blend of high octane gas…

  • avatar
    beefmalone

    If we were really worried about fuel economy, we’d quit watering down our gas with 10% ethanol.

  • avatar

    Electric cars make all this topic meaningless.


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