American fuel vs European fuel – Fuel quality on both sides of the Atlantic explained

Fuel in the US is really bad compared to Europe and the rest of the world” – is a very untrue statement. Fuel in the United States is as good as anywhere else in the world. What changes is how Americans describe their fuels in terms of quality – octane number. They use a different system so their numbers do not translate well into the octane numbers that the rest of the world uses.

How is fuel quality measured and rated

Gasoline quality is measured experimentally but using different tests. Depending on the test that is done to control fuel quality, we get

  • Research Octane Number (RON) , used in Europe and most of the world
  • Motor Octane Number (MON)

Because two different tests define RON and MON, with MON testing done under more difficult conditions, MON number is always lower than RON.

Europe vs the States

In Europe, gas stations describe different types of gasoline based on their RON rating. It is typical to have 100, 99, 98, 97 or 95 RON with prices varying accordingly. In the States the descriptions look a lot like RON, but they are not.

Pump gas

In the United States gas stations describe the types of gasoline based on the Pump Octane Number (PON). That number is the average between RON and MON. This causes many problems.

If a fuel is 98 RON then it will be 93 PON -> 93 PUMP
If a fuel is 95 RON and 87 MON then it will be 91 PON -> 91 PUMP

Is American fuel quality bad after all?

No, not at all. Contrary to popular belief, fuel quality in the States is as good as anywhere else in Europe. Most Americans think that because they are running 91 octane fuel, their engine will blow up. It is the same as if they were using European 95oct fuel.

In our website you will find RON ratings required for each remap stage.
98/100 RON means you will need to use 93 PON in the States.

95 RON means you can use 91 PON in the States.

Everywhere else in the world, 98 RON and 95 RON gasoline usually are fit.Anything lower then that and your modern engine will have a lot of trouble adjusting, even on the stock calibration.

Ethanol addons

There are a few countries around the globe that are using Ethanol in their fuels. One of them is Brazil, where by law all fuels need to have at least 20% Ethanol. This usually does not have an impact on power, but it does bring slightly higher fuel consumption. As long as the fuel type gets a 95RON or 98RON rating, it is suitable for use in the car and with our remaps.


  • Simon Posted January 27, 2019 10:34 pm

    There’s a caveat though. Europe only has 95 (“premium”) and 97/98 (“super”). These are indeed roughly the equivalent of US premium and super. But the US (and some countries like Australia) also have a lower “regular” level.

    • Carl Posted March 3, 2019 10:23 am

      I just put 100 Octane (ron) Shell β€œv-power” into my car in Switzerland. So there is higher than 98 in Europe.

      • Dennis Posted June 6, 2019 7:11 am


      • Ariel Posted July 30, 2021 3:30 am

        Thats Because everyone knows the Swiss are better than europeans πŸ˜‰

    • Mark Posted May 17, 2019 3:41 am

      In Luxembourg city area Station on route de longwy is an Aral with ultimate 102
      Luxembourg has cheapest gas.

  • formata Posted February 19, 2019 2:50 am

    so base on what you are saying i need to put the top gas in USA so i can have the base gas in EU because in USA you have lower regular gas so in the end EU have a better gas

    • Eric Posted March 11, 2019 8:32 pm

      Caps lock is stuck on.
      it depends on the car. most cars (especially American cars) are designed to run on 87 octane and won’t do anything if you high octane fuels in. newer cars (even American models) may be able to take advantage of the advanced timing allowed by higher octane fuels. Ford’s ecoboost engines definitely prefer high octane fuel, even though they are advertised as 87 octane friendly.

  • Dr Daytona, Ezekiel Posted March 22, 2019 12:44 am

    OK. Well what about the diesel fuel that is sold in the US to their consumers’ vehicles?

    In the UK and I assume other European countries, that its performance and quality, such as Shell’s V-Power; is rated and based primarily on a higher cetane number and a lower octane number.

    Conversely, a lower-octane, higher cetane in diesels make its combustion quicker and a more efficient burn….

    Does the average American have a choice of ‘premium diesel’ option?

    Kind regards.


    • Stelios Alexandrakis Posted April 6, 2019 10:18 pm

      Unfortunately we would not know much about the US diesel grades. We have very limited experience with what is available, State-wise because the State emission laws affect diesel, gasoline and their additives. It is the additives that make them better or worse fuels.

    • Matt T Posted September 26, 2019 4:16 am

      No, in the U.S. there is only one diesel. In cold states they switch to a winter blend diesel. I think it’s just an anti gelling agent.
      In Massachusetts, we have 87, 89, & 93 gasoline. Some states only go as high as 91, and some have 85 or 86 “economy” or “Sub regular”

  • CART forever Posted July 6, 2019 2:56 am

    It’s “Illegal” to put high Octane Gas in street vehicles in the USA thanks to the EPA (Environmental Pollution Agency…search EPA MTBE carcinogen) considering it only for off road and aviation use.
    Our Diesel isn’t the same as the Europeans show running in their “breathable” exhaust cars. The US’s “reformulated/oxygenated” Diesel smells worse than the old high sulfur diesel, again thank Clinton’s EPA.

    • Matt T Posted September 26, 2019 4:19 am

      The United states Environmental protection agency.
      ……..And each state has an environmental protection department with environmental police.

    • Travis Posted January 2, 2020 3:49 am

      What you are saying isn’t strictly accurate.

      First, let’s define high-octane. I’m assuming you are referring to fuels that are 100+(US) or 108+(Euro) octane and over. Sure, according to law, one must use gas that is designed for and has been taxed for road use.

      Your point is moot, though, as no vehicles that are sold in the US would even receive any benefit from running such a high-octane. A race engine that has been built with a very high compression ratio certainly could, in order to avoid pre-detonation. However these, are not cars that people would use on the road to begin with. All legality aside, the cost of running this level of octane in a street driven car would be astronomical!

      • Ronald Posted February 11, 2020 7:51 pm

        Caps lock? The late Great Dodge Challenger Demon and the 2015 and 2016 chevy corvette z06 (GM part number 12677967 )could be calibrated to use 100 AKI fuel.

  • Tony Posted November 14, 2019 3:53 am

    Isn’t there more too it than octane rating?

    Does gravity density rating come into it?

    I was lead to believe that carburetor equipped engines such as dirt bikes or drag cars etc need re-jetting when transferring between countries due (in part) to the differences in their density ratings?

    Thanks, TP

    • Stelios Alexandrakis Posted January 17, 2020 4:20 am

      You will probably find that gasoline has the same specific density between different countries. The chemical composition of the fuel itself does not change, what does change is the additives that are used in each region. They depend on each country’s emissions legislation. Other than this, you can run an american car on european 95+ron fuel types without issues. You cannot use 89oct (pump) gasoline on european cars.

  • John Posted December 31, 2019 4:17 am

    What about non ethanol gas in the US? Every once in a while I put a tank of 93 octane in just to clean it out (at least I think that’s what I’m doing) Is non ethanol a good fuel to use and if so which octane is best?

  • T Posted December 28, 2020 1:04 pm

    So let me get this straight.

    If a car is tuned in the USA, it is tuned probably for 91 PUMP, which translates to 95 RON. Putting anything above that is not a problem.

    But my question is, if the car is Imported to Europe from USA, does it need re-tuning? Can i just put 95 RON and above, if the car is tuned for 91 PUMP in USA?

    Are the octane number the same and do not need tuning?


    • Stelios Alexandrakis Posted February 7, 2021 10:00 pm

      Yes you can do that. It will run just fine, as the lowest quality available Europe-wide is 95RON and it is better than most grades found in the States.

  • Eric B. Posted July 28, 2021 9:53 am

    East of the Mississippi River premium fuel is usually 93 octane and 95 octane if you get lucky at a Sunoco station.

    West of the Mississippi we have 91 octane horse piss, and that is why I regularly add 5 gallons of 100 octane to my 15 gallon tank. Yeah, at $8. per gallon I it’s spendy. But my 2019 CX-5 GT Reserve (2.5 L. turbo, AWD) evidently has a fuel map that permits it to utilize even full 100 octane gas. Yeah, I did that once, 1/2 tank of pure 100octane, but don’t tel my wife. Anyway WOW! that higher octane really peps up my acceleration.

    “WHY”, you ask, “do you only get 91 octane gas west of the Mississippi? Damned if I know. But Q-anon says its a conspiracy by those elitist, Ivy Leaguer, Birkenstock wearing, BMW driving eastern Deep State conspirators. And you can always believe whatever Q-anon says, RIGHT?

  • Lucas Posted November 21, 2021 3:05 am

    We also got pure ethanol in Brazil, 112 RON. It translates into 30% more fuel consumption, but its 100% more fun. Most of our cars are built with are flex and have a higher compression ratio.

Add Comment

Your email address will not be published. Required fields are marked *