What would happen if you use E100 ethanol instead of E85 on flex fuel vehicles such as Chevy Tahoe or Impala?

Question

My friend is considering buying a ethanol fule vehicle. However, he wants to use E100 isntead of E85. I understand E100 is not available in the U.S. but in his country.

Does E100 works same as E85 on GM or Ford made ethanol vehilces? Please advice.

Answer 1

It will develop a lean misfire, and will have detonation problems.  No, E85 does not operate the same and the Delphi module that calculates fuel requirements does not have the maps installed to handle E100.

Answer 2

It would have the same effect as using higher octane gasoline then your vehicle is rated for.  In all but the most high performance of vehicles, there will be absolutely no difference between using E85 and E100.

If your engine is knocking, or showing other signs that it needs a more combustible fuel, then by all means try the E100.