Does Europe Have Higher Octane Gas? RON vs MON vs AKI

Octane Rating – RON vs MON vs AKI. Often people ask “Why does the US have such low octane gas at the pumps?” They state this assuming European fuels have a significantly higher octane, when in fact it simply comes down to how we label our fuels. Most countries show the RON, or Research Octane Number. In the US, as well as a few other countries, we show the AKI, or Anti-Knock Index, which is the average of both the RON and MON, or Motor Octane Number.

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34 thoughts on “Does Europe Have Higher Octane Gas? RON vs MON vs AKI

  1. gluino says:

    Decent explanation. It raises the question as to why we don't demand all petrol brands publish both RON and MON ratings of each of their products.

  2. How do they get 101-104 octane RON when they test ethanol E85? 104% iso-octane is not really possible..

  3. jurrien75 says:

    Thanks! I didn’t know this.

  4. Kannietwo says:

    Germany has up to 105 RON Fuel ^^

  5. Free-me says:

    Thanks it make sense now..

  6. What does Japan use since their Octane fuel is quite high also?

  7. MrTinCanHead says:

    Could You talk about ethanol as fuel and why aren't we just using it in our cars instead of gasoline? It's way cheaper and from what I read we can use it in normal engines with almost no change. And i think they use it in some sports. besides we already use some % of ethanol in our gasoline.

  8. I´v seen  more water comming out of the exaust pipes on American cars than on European ones! Explain that.

  9. We use mon, with oz I think,why can't everyone use the same number!! So this helped me,and lost me at the same time:) lol we have 91 95,and 98!. I'll just come back and watch this when I'm more awake!! Lol

  10. Callandor says:

    This is what I always suspected. In Canada, normally 94 is the highest. Shell V-Power at 91.

  11. EX Elton says:

    so the lowest fuel here in europe is the same as usa premium? lol Now imagine those gtrs on youtube with our 98 :D

  12. in asia malaysia……we have ron 95 ron 97 and the highest ron is ron 100….

  13. Chris Shazam says:

    Is US gasoline the same as European gasoline? so I can drive my American car over there

  14. Jebach says:

    I don't get one thing though. How can E85 have an octane rating of 100+ RON when RON is the measurement of the percentage consistency of the fuel that is a special isomer of octane that doesn't misfire, the 1,3,3-trimethylpentane. So for example, 95 RON would be 95% 1,3,3-trimethylpentane and 5% heptane (supposedly worst fuel in terms of knocking). So does 105 RON ethanol then run like a 105% 1,3,3-trimethylpentane or what? :D

  15. I use100,thank you.

  16. Grobo Garage says:

    Feels good to be able to get compettion 102 at the pump in the netherlands:) untill you see the price of 14 dollars a gallon ofcourse..

  17. Michal Mocny says:

    Why does ignition timing affect knock? Makes total sense why compression ratio, altitude, and other factors affect knock — but why ignition timing? Doesn't knock come before ignition anyway?

  18. Aaron P says:

    FORD OF EUROPE says that there basic cars need 95 RON. But in the USA the same motor there calling for 87 OCTANE

  19. kennysandhoj says:

    I never put anything but 98 RON fuel in my car. I don't believe that is avaliable at all in Amurrica :)

  20. Steve Keller says:

    Most people are totally wrong in their knowledge of octane ratings. Actually, the higher the octane means that it has additives that retard the explosiveness of the fuel. High compression cars like porches, Mercedes, Ferraris etc are high compression so they need higher octane gas that won't ignite too early. Low compression cars need the lower octane which is a more explosive fuel. I know, i didn't find that out until very recently when i took a small engine repair class!

  21. nazo333 says:

    Why not just have everybody purely use MON instead? Lol

  22. vavhab says:

    So lets say 87 AKI = about 91RON
    There is no 91RON fuel in Europe. :D The lowest is about RON95. In the most European countries you can buy RON95, RON98 and some premium fuels….
    What about this?

  23. D. G. says:

    And to add to the mix of things my Aircraft & Powerplant textbook states about AVGAS:"there are 3 grades of fuel in general use: 80/87, 100/130, & 100LL".The 2 numbers indicate the lean mixture and rich mixture octane rating numbers, this is used at all airports worldwide, this rating is the only system used internationally. Still another example on how you can rate the same substance differently! Remember though AVGAS still uses lead as an antiknock/octane booster

  24. Daniel J says:

    Hi, I am from EU and I have Ford Mustang GT 5.0 it is written that I have to fill up with 93 fuel, but we have 95 and 98, so I have to fill up with 98?

  25. Kostas Z. says:

    Well still Europe has higher octane gas. In US gas stations I see 87, 89 and 91 as the premium. 93 at some cases. So if 91 AKI=95 RON, it means that the best fuel US has its equal to the worst in Europe. Because we have nothing below 95 RON and we also have 100 RON.

  26. V8 Powerr says:

    +Engineering Explained Yes Europe has better fuel because 95 RON (91 US rating) is the worst you can buy in EU, while in america 87 (91 RON) is the worst you can buy and then the premium is 92 which makes only 96 RON, while in Europe premium is 98 RON (94 US rating) and Shell V-Power is 100 RON (95 US rating). And also there's no ethanol in fuel in europe.

  27. LongTimeAgo says:

    What the hell is 102 RON then? Some pumps sell this as "high performance racing" fuel.

  28. Jake Gilmour says:

    Isn't it true in some states such as Colorado, they cannot get the 'super' high octane rated fuel (Euro 98 RON) (US 93 RON) ?
    +Engineering Explained

  29. I prefer to keep it simple: The motorcycle gets the best Ethanol Free gasoline I can find (Typically Super/Premium) The truck gets the cheap stuff, because it gets craptastic mileage no matter what it gets fed.

  30. 888berg says:

    Your engineering knowledge is always appreciated!

    I've got a video idea if you're ever interested in suggestions; whats the deal with Kawasaki motorbikes and their 'rosette' style brake rotors? Instinctively one would have thought that decreasing surface area would be a bad thing..

    So perhaps initial bite or over fancy gas expulsion at play.. hmmm, interested to hear your thoughts.

    Cheers, please keep up the awesome vids for us all :)

  31. spankmeister says:

    87 AKI = 91 RON
    89 AKI = 93 RON
    91 AKI = 95 RON
    93 AKI = 98 RON


    And all these discussions about the US vs EU… Who cares just put some gas in your tank and drive what does it matter which system is better?

  32. ixyzyxi says:

    So even here Amerika has to say: screw everybody else we make our own system.

  33. vominator says:

    Why do people even care?  where are all the high horsepower cars?   The fact there are a few autobahn monsters and random supercars in Europe doesn't make up for the fact that there are far more of those cars in the US, and 99.9999999999999999999999999999999999999999% of cars in europe are sub 1 liter 3 bangers.

  34. branot89 says:

    Why does Mazda's SkyActiv engine has 13:1 comression ration in USA, but 14:1 in Europe? I think European gasoline is better

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