Gasoline E 85 vs E 89 for a ford focus 2001?

I was wondering it is possible to une 85 gasoline instead of E 89 and adding octane booster in tank, thanks for answers

Hold on. First you need to get your gas terminology right: E85 is a designator for a gasoline and corn mix that has 85% ethanol. If your vehicle is not a “flex fuel” vehicle (check your manual), using E85 will damage it. Your focus is not a flex-fuel vehicle as far as I know.

There is no such thing (in the US, anyway) as E89, which if it existed would be 89% ethanol, 11% gasoline. Standard gas grades are 85 (in mountain areas), 87, 89, and 90-93.

I believe the Focus is OK with any grade of gasoline (the manual recommends 87) provided it is gasoline, not E85. Fill up with regular unleaded.

What’s “E89” exactly? Your manual calls for 87 octane which would be sold as “regular” in most areas. To my knowledge the 2001 Focus is not a flex-fuel vehicle so it wouldn’t be wise to use E85 in it. Please understand that that “85” in “E85” is not the octane rating. It’s the percentage of enthanol in the fuel.

Please don’t try to use E85 in your Focus. It will probably cause all sorts of problems since it’s mostly ethanol and not much gasoline.

You can safely use 87 octane “regular” gas, which is 100% gasoline, in your Focus. You don’t need 89 octane, or anything higher than 87.

There is no such thing as E89. There is 89 octane gasoline, but it has nothing to do with “E,” which designated ethanol content, not octane rating. They are two entirely different things.

It appears that you want to use 85 (maybe 87?) octane gasoline instead of 89 octane. Your Focus is meant to run on 87 octane gas. If you can find 85 octane, you are probably in the Rockies, and 85 octane will work, too. I caution you not to use E85 as the other posters did. Your Focus has parts that will be damaged by all than ethanol.

Well, if 85 octane is available, then they probably live somewhere high up like Colorado. If that’s the case 85 OCTANE is fine, but E85; Ethanol(corn fuel) blend 85%; is not.

No one here truly understands what your question is, because you truly don’t understand what the situation is, or are unable to clearly express your thoughts to us.

Did you just recently move from a low altitude location to a high altitude location?

In high altitude locations, like here in Denver, we have 85 octane gasoline.
This replaces 87 octane at lower altitude places.
No, you don’t need to use octane booster, you car will work just fine on 85 octane gas.

We also have E 85 gasoline, which is a mostly ethanol based gasoline.
This should only ever be used in a vehicle that has the FlexFuel designation on it.
If you try to use this gasoline in a non-flex fuel vehicle, you can cause damage to the vehicle.

Hopefully this post helps clear things up for you.


I think you might mean 89 octane which would actually be E-10 or 10% ethanol. That you could use in your Focus. I would not use the E85 in it.