E85 is a different beast though, it's not as comparable as 91, 95 and 98 octane. It's in a league of its own.
The cooling effect/RON is a massive step up and with that ability for the ECU to throw timing at it, can definitely hit that 10%+ figure quite easily.
The old 100 octane could have quite possibly done the same, obviously not quite as effectively as E85.
Be very careful throwing E85 at old Toyotas as well, the fuel seals, hoses and o-rings have already had a tough life. The E85 will do its best to destroy them rapidly. It will also clean the years of deposits out and send them towards your fuel filter and injectors.