Gas: 91pure VS 93 w/ ethanol

[BeachM5nster]

Preference and thoughts:

I test the gasoline anywhere I buy gas near my house for ethanol just like recreational pilots have to do because ethanol = death for them..

I can get good pure gas at one place but its 91 octane.

everywhere else that advertises pure 93 actually has ~5% ethanol

i can get supplemental 110 etc no problem

-Would you rather run 91 pure or 93 with 5% ethanol ?


I know ethanol will dry things out, seals rubber etc.
but do you think the f10 M5 is made to handle ethanol being more modern? or should I run pure gold all the time not even with <5% ethanol?

if I get the Pure 91 how much Pure 110 (or whatever) from VP can i add to get a nice clean pure 93octane in my tank?