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.

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