When Gm says this, what do they really mean?
Do they mean you should only use 92+ octane?
Do they mean you should use 92+ octane when possible, but the car will "live" on 89?
or does it mean you can run it on 87 octane and occasionally put the good stuff in it or put in a octane booster?
I had a 2006 Impala SS with the 5.7L and it recommended the Premium and that is all I used. I always wondered though.