I have been running my 2003 on 91 octane unleaded,.. and was told today that I should use either 96 or 98 octane unleaded. I did not think that a FireStorm had that higher compression ratio.
So far I have not had any drama,..
I had it Dyno-tuned today with new mufflers and a K&N filter,.. and it returned .. 105 hp .. on the 91 fuel. ( up from 95 hp. )