91 is the highest here in LA but then again, we have the most amount of additives in our fuel to kill power (and lower emissions at the same time). I've once filled half my tank with 100 octane at a shell station 40 miles from home (it was on the way to the track) but it was $7.95/gallon! I did find a gas station that specializes in other types of fuels such as diesel/diesel2 and leaded 110 octane fuel, but they're always closed when I drive by at night-time. WHY THE HELL ISN'T THERE AN E85 STATION NEAR MY HOUSE!?