What is the highest percentage of ethanol my car can take? I have a ford escape 2007. I have been putting in either 10% or 20%. Thank you


Regular vehicles can handle 10% ethanol without too much of an issue. This is the normal blend (E10) which is required by the US government (I don't know what is specified elsewhere in the world). Unless your vehicle was specifically setup as a "flex-fuel" vehicle, it won't be able to deal with more than that. Ethanol fuel itself is usually an 85% ethanol/gas blend, and is called E85.

Vehicles which are setup as flex-fuel vehicles have more to them than just parts which can stand up to the corrosiveness of the ethanol. Since ethanol has less energy per unit than gasoline (petrol), it requires more of it to produce the same amount of power out of the engine. The flex-fuel models have a way (depends on the vehicle manufacture as to the how) to discover what type of fuel is being used and adjust the amount of fuel which is injected. If you are running E85 in a car which is not setup for it, your power output will be way down as compared to running E10. There are other factors as well.

To protect your vehicle, use E10 if it is not registered as a flex-fuel model.


I know this is an old question, but I disagree with the answer. It was incorrect in 2014 and is incorrect now.

If your car was built after 2001, the EPA has approved fuels up to 15 percent ethanol (E15).

The reason the EPA didn’t approve E15 for cars made between 1996 and 2000 is because it didn’t have the funds for vehicle testing.

Ethanol has been around for a long time. In fact, Henry Ford started out using ethanol in his first vehicle production line. If you’ve heard that ethanol damages fuel lines or gaskets, the fact is, most damage is due to toxic aromatics like benzene and toluene that commonly exist in gasoline today.

The EPA limits its certification to E15 unless vehicles are certified on E85. The auto industry has to certify vehicles under EPA rules and guidelines. The EPA does not allow vehicles to be certified on any other blends.

Most testing to approve E15 also included E20 testing data, which showed E20 provided a better performance than E15.

Most cars can adapt up to blends of 30 percent ethanol.

Most vehicles that are 2001 and newer have been tested for up to E15. Some of the testing included E20 and E30 without problem.


  • hmm, "I heard ethanol is hygroscopic, whats that mean?" didn't make the "FAQ" list on that site..
    – agentp
    Mar 21 '18 at 0:16
  • Hygroscopic means that it mixes with water. This is the main benefit (to the vehicle owner) of ethanol-blended fuels. If there is water in your fuel (happens due to condensation all the time), it will mix with the ethanol in the fuel, and will then burn in your engine. With no ethanol present, the water would accumulate at the bottom of the tank, because it is more dense than gasoline, and it would be pulled into the engine, where it would stall the engine, because it obviously does not burn. In the winter, water in the fuel can cause freezing, which ethanol also helps to prevent.
    – Elkvis
    Feb 6 '19 at 19:17

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