[A.J.]

Here in Montreal we have 3 grades of gas: 87, 89 and 91 octane.
I noticed that the pump says that 87 and 89 "may contain up to 10% ethanol" but there is no such label on 91.

While I heard that higher octane might not give a boost in FE, I was wondering, would there be any advantage of driving on 91 (E0) rather than 87 (E10)?

Thursdays, the difference between 87 and 91 is only 11.4 cents/gallon rather than 22.8. Do you think it's worth it? (keeping in mind gas here is about $5.14/gallon)