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I have been putting 1/2 tank of E-85 1-2 times a month in my 2000 xtera. Am I hurting my engine?

Is your Xtera a certified flex fuel vehicle? If not, then you are hurting your engine. Ethanol is, for lack of a better word, corrosive, compared to gasoline. Many of the seals and gaskets that work fine in a gasoline environment will fall apart in ethanol. Real FFVs have gaskets and seals that are engineered to withstand the environment.

See Click and Clack’s discussion of this.

Yes. The fuel system in your vehicle isn’t designed to handle the corrosive nature of E85.

The engine can also be damaged by burning holes in the pistons. A coworker did this to his Ford Ranger running E85 in it.

If you look in your owners manual, it will warn you not to use a gasoline in your vehicle with a rating of higher than E10.


It doesn’t appear as if the 2000 XTerra was built to run on E85 so YES, you’re hurting your engine!!

Why would you want to do this? Did you read your owner’s manual?

E85 just lowers your MPG so much that it probably doesn’t even save money if your car was built to handle it.

Absolutely. Your engine was not designed to use E85.

Personally, I think it is possible you are not harming your engine. However, your fuel system was not designed or built to handle such high concentrations of ethanol. You are probably damaging components of your fuel system, and although, technically, these parts are not part of the engine, they are expensive to replace.

You should stop doing what you are doing and hope for the best.