As I understand it higher octane is meant to prevent pre-ignition form pressure and or heat, the higher the compression the higher the chance of pre-ignition. Some engine designs are more sensitive to this than others. I kinda figured the 2zz would fall in that class.
But, Counter Point, (Dan Ackroyd voice); "Jane, you ignorant slut..." ala local news consumer hotlines and the like comes reports of some vehicles running just fine on lower than listed octane ratings, so I had to bounce it off of the sounding board that is eCelica.com.
A feature of the GTS that is really making me feel good about my car buying decision right now is the Jekyll and Hyde relationship between gas mileage and high Performance.
The geniuses of this car is that the higher power is on tap at the higher RPM's but down in the low RPM's its gets a miserly 23/32, I must admit that It makes for a good feeling when I'm filling up next to an SUV. Celica has amongst the best gas mileage to Performance ratio of everything else in its class.
Thanks to all for the feedback.