Interesting thread on the effects of higher octane on lean burn:
http://ecomodder.com/forum/showthrea...wer-12499.html
This thread on ethanol concerns me. Sounds like poison for cars older than 1995:
http://ecomodder.com/forum/showthrea...age-18326.html
I'm definitely leaning towards the 91 octane fuel. As an added bonus 91 octane from shell has more v-power.