Well, I guess I started this damn thing, but to be honest with the forum, I'm kinda glad I did. It sounds like many of us just want to know the real answer...no argument or challenges in mind. It all started with the marketing guy at Cadillac who brilliantly stated in the owners manual that the engine performance would be better with a higher octane fuel in a standard, non-modified 3.6L CTS. Sorry to question the feedback about how the car lays rubber with hi-test (in the east we have shitty weather, but can still easily buy 93-94 octane fuel!), but, frankly, the ECM can not do that if the car is designed to run 87 octane fuel and make 255hp unless the car is actually designed to make around 275hp and detunes itself with a lower octane fuel. By the way GM, if your listening, I do really like the car. My Viper is a little upset 'cause I drive the CTS alot more than the previous daily driver I had.